Learn how to make the cotton soft and fluffy purple sweet potato chiffon cake dotted with chunks of purple sweet potatoes.
Chiffon cake gets TONS of love in this house. Whenever I made chiffon cake, it disappears like in a matter of one day! My two kids who aren’t really fans of cakes will eat this moist, soft, and airy chiffon cake like they are candies 🙂
When I saw purple sweet potatoes go on sale, I always grab them. I love eating them on their own or making desserts with them. This super-soft purple sweet potato chiffon cake is one of my favorites. The subtle pastel color and biting into some tiny chunks of purple sweet potatoes are just awesome.
Which purple sweet potatoes to use
You can use any two of the following for this recipe. I usually use Okinawan purple sweet potatoes because they are easier to find where I am compared to Stokes purple sweet potatoes.
1. Stokes purple sweet potatoes
I seriously not sure if there’s a different name for this but I saw many refer to this type as Stokes Purple Sweet Potatoes
Purple Sweet Potatoes (Purple Yam) with brownish purple skin
2. Okinawan purple sweet potatoes
Okinawan purple sweet potatoes have lighter pale skin, but a deep purple color on the inside. Who would have guessed right?
Okinawan purple sweet potatoes
Okinawan Purple Sweet Potatoes
Can I use purple yam or ube to make this chiffon cake?
Because ube is a yam and not a potato, I didn’t include it as one of the purple sweet potatoes. But, yes you may. Simply replace in the same quantity.
Important Tips for success
1. Separate the yolks and the whites while they are still cold. Then leave them at room temperature before using
2. Never EVER grease your chiffon tube pan anywhere. The cake needs to cling to the pan to rise
3. The purple sweet potatoes may change color because of acid/base balance. It doesn’t affect the taste of the cake, just the color. I recommend adding purple sweet potato powder, purple food coloring, or ube extract so you still have that nice pinkish purple hue
4. Cut the sweet potatoes into tiny pieces so they won’t sink to the bottom of the cake during baking
5. The baking temperature and the time I listed out are just for reference. You need to know your oven and adjust accordingly
6. Invert the cake immediately after banging the pan on the counter 3-4 times to minimize shrinkage
7. Do not attempt to unmold the cake until it has cooled down completely
How to make purple sweet potato chiffon cake
1. Separate the egg yolks from the whites and let them sit out for 20-30 minutes at room temperature. The meringue whips better at room temperature
2. Peel the skin off sweet potatoes and cut them into tiny pieces. Steam over high heat for about 5-7 minutes. and some for mashing. Mash the potatoes while they are hot. Set aside
Remove the amount required in the recipe and cut into tiny pieces
3. Whisk the egg with mashed sweet potatoes, sugar and cooking oil, then add coconut milk and ube extract or purple food coloring. In a separate mixing bowl, mix the dry ingredients
4. Place the egg whites in a clean bowl. You will have trouble whipping your meringue if there’s a trace of grease in your utensils or bowls. Beat the egg whites on medium speed (speed 6 on KA) until frothy, add cream of tartar/lemon juice/vinegar and whip until it turns whitish, about 1 minute. Gradually add the sugar as you beat, about 1 minute apart. Continue whipping on medium speed until you reach a stiff peak with a slight bent on the tip when you lift the meringue up
5. Gently fold 1/3 of the meringue into the thick batter using a whisk. Continue on with the second 1/3 of the meringue again to mix. Continue to do this until you are done with the meringue
6. Switch to a rubber spatula. Swipe down and fold over motion again to make sure we are combining the batter and the meringue. Sometimes some batter at the bottom of the bowl didn’t get mixed with the meringue
7. Coat the tiny pieces of sweet potatoes with about 2-3 teaspoons of cake flour. Shake off excess. This will help to prevent the potatoes from sinking to the bottom during baking
8. Add the coated sweet potatoes into the batter and gently swipe down and fold over again using a rubber spatula for 3-4 times to combine
9. Gently pour the batter into the pan. Give the pan a few gentle shakes to even out the batter. Give the pan 3-4 firm taps on the counter. Use a skewer to run a zig zag motion to pop any large bubbles inside the batter. Tap the tube pan on the counter 3-4 times again before putting into the oven
10. For 7 inch cake, bake in a preheated oven for 60 minutes. For 8 inch cake, bake for 65-70 minutes on the middle rack or until a cake tester comes out clean with just a few dry crumbs. It shouldn’t be wet. The top of the cake should be dry to touch and springy when you gently press on it
11. Once out of the oven, give the pan 3-4 taps on the counter to prevent the cake from sinking. Then carefully invert the pan upside down immediately. Your chiffon pan may have the little stands for you to inver. Please don’t be tempted to remove from the pan if it’s still warm. It takes about one to two hours to cool down completely
12. Once it’s cool down completely, use an offset spatula to run through the edge of the cake to help release the cake. Use a skewer to loosen the tube area. Gently push the base of the pan up. Use an offset spatula again to run through the bottom of the cake to help release it from the base of the pan
Did you make this super-soft purple sweet potato chiffon cake recipe?
I love it when you guys snap a photo and tag to show me what you’ve made 🙂 Simply tag me @WhatToCookToday #WhatToCookToday on Instagram and I’ll be sure to stop by and take a peek for real!
This recipe was last published in October 2018 and I have updated it with new photos, more information for success and a video tutorial on March 7, 2022.
Super Soft Purple Sweet Potato Chiffon Cake
Ingredients
FOR 7-INCH TUBE PAN:
WET INGREDIENTS:
- 4 egg yolks from large eggs about 55-58 gr each (with a shell)
- 67 gr mashed purple sweet potatoes
- 16 gr sugar
- 90 ml coconut milk you can also use dairy or nut milk
- 27 ml cooking oil
- 67 gr tiny pieces of purple sweet potatoes
- ½ tsp ube extract
DRY INGREDIENTS:
- 80 gr cake flour plus more to coat purple sweet potato pieces
- â…› tsp salt
MERINGUE:
- 4 egg whites room temperature
- ¼ tsp cream of tartar or 1/2 tsp lemon juice or vinegar
- 53 gr sugar
FOR 8-INCH TUBE PAN:
WET INGREDIENTS:
- 5 egg yolks from large eggs about 55-58 gr each (with a shell)
- 80 gr mashed purple sweet potatoes
- 20 gr sugar
- 120 ml coconut milk you can also use dairy or nut milk
- 30 ml cooking oil
- 80 gr cubed cooked purple sweet potatoes
- ½ tsp ube extract
DRY INGREDIENTS:
- 100 gr cake flour plus more to coat purple sweet potato pieces
- ¼ tsp salt
MERINGUE:
- 5 egg whites room temperature
- ½ tsp cream of tartar
- 70 gr sugar
Instructions
- Make sure your chiffon cake pan does not have a non-stick coating or your cake will not rise. The cake needs to cling to the side of the pan to rise tall
- Preheat your oven to 330 F (165 C) for a conventional oven. If you have a convection oven, I suggest lowering the temperature by 25 F (15 C)
STEAM THE PURPLE SWEET POTATOES:
- Peel the skin off sweet potatoes and cut into tiny pieces. Steam over high heat for about 5-7 minutes. Remove the amount required in the recipe and cut into tiny pieces and some for mashing. Mash the potatoes while they are hot. Set aside
- Separate the egg yolks from the whites while they are still cold because they are easier to separate when they are cold. Then let them sit out for 20-30 minutes at room temperature. The meringue whips better at room temperature
PREPARE THE CAKE BATTER:
- Whisk the egg with mashed sweet potatoes, sugar and cooking oil, ube extract/food coloring, then add coconut milk. Sift in the cake flour and salt
WHIPPING THE MERINGUE:
- Place the egg whites in a clean bowl. You will have trouble whipping your meringue if there's a trace of grease in your utensils or bowls. Beat the egg whites on medium speed (speed 6 on KA) until frothy, add cream of tartar/lemon juice/vinegar and whip until it turns whitish, about 1 minute. Gradually add the sugar as you beat, about 1 minute apart. Continue whipping on medium speed until you reach a stiff peak with a slight bent on the tip when you lift the meringue up. Then turn the speed to lowest and whip for 1 minute to smooth out large air bubbles
FOLDING THE MERINGUE:
- Gently fold 1/3 of the meringue into the thick batter using a whisk. Continue on with second 1/3 of the meringue again to mix. Continue to do this until you are done with the meringue and switch to a rubber spatula. Swipe down and fold over motion again to make sure we are combining the batter and the meringue. Sometimes some batter at the bottom of the bowl didn't get mixed with the meringue
- Coat the tiny pieces of sweet potatoes with about 2-3 teaspoons of cake flour. Shake off excess. This will help to prevent the potatoes from sinking to the bottom during baking
- Add the coated sweet potatoes into the batter and gently swipe down and fold over again using a rubber spatula for 3-4 times to combine
BAKING:
- Gently pour the batter into the pan. Give the pan a few gentle shakes to even out the batter. Give the pan 3-4 firm taps on the counter. Use a skewer to run a zig zag motion to pop any large bubbles inside the batter. Tap the tube pan on the counter 3-4 times again before putting into the oven
- For 7 inch cake, bake in a preheated oven for 60 minutes. For 8 inch cake, bake for 65-70 minutes on the middle rack or until a cake tester comes out clean with just a few dry crumbs. It shouldn't be wet. The top of the cake should be dry to touch and springy when you gently press on it.
- Don't be alarmed if your cake has some cracks on top. What you are looking at will become the bottom of your cake
COOLING:
- Once out of the oven, give the pan 3-4 taps on the counter to prevent the cake from sinking. Then carefully invert the pan upside down immediately. Your chiffon pan may have the little stands for you to inver. Please don't be tempted to remove from the pan if it's still warm. It takes about one to two hours to cool down completely
- Once it's cool down completely, use an offset spatula to run through the edge of the cake to help release the cake. Use a skewer to loosen the tube area. Gently push the base of the pan up. Use an offset spatula again to run through the bottom of the cake to help release it from the base of the pan
STORING:
- If you have the patience to wait, once the cake has cooled down completely and you have unmolded the cake, wrap it up in a cling wrap or store in an air-tight container and the flavor and texture gets even better the next day
- The cake can be kept at room temperature for 2-3 days if it's not very humid where you are. Keep in the fridge, well-covered to prevent drying out if it's really humid
Notes
- Â For 6 inch tube: use 3 eggs and multiply by 0.75 the rest of the ingredients. Bake for 50 minutes
- For 9 inch tube: use the same recipe with 8-inch tube pan recipe (the one I posted on the recipe card)
- For 10 inch tube: use 8 eggs and multiply by 2 the rest of the ingredients. Bake for 70-80 minutes
23 comments
I want to try this cake but hve a query,
The small pieces of the sweet potato are also steamed ? Or are they raw ?
Hi Venti, yes, they are cooked too! all of the potates used in the recipe has been cooked. I hope that helps!
Hi! Obsessed with this recipe and really excited to try, just wondering how much of the ingredients I should use if I want to fill 2 8inch pans and 3 6inch. Or also if I can fill these pans but not to the top and use a lesser cooking time?
Thanks!
If you want to bake two 8 inches cakes, you can just double the recipe under 8-inch tube pans. If you want to bake three 6 inches, my “guesstimation” would be you want to 1.2x the ingredient for one 8-inch cake.
You can certainly not fill it up to the top, and depending on how much you fill it, you can reduce cooking time by 5-10 minutes. I can’t tell you for sure and this is something you may have to experiment with a bit. The cake should be dry to touch on top and springy when you lightly press on it. If you insert a cake tester, it should come out clean with a few sticky crumbs is okay, as long as it’s not wet. I hope that makes sense.
Hi, I was wondering if there is a way that you can just make a ube chiffon cake using only ube extract using this recipe? If I can substitute the actual sweet potato with ube extract how much should I use and if there is other ingredients that I need to adjust? I have a 7in tube pan. I already made the pandan chiffon cake using your recipe so I can’t wait to try your other flavor like black sesame and this one.
If you want to use only ube extract, I suggest using the same pandan chiffon cake recipe by replacing the pandan juice with milk or coconut milk and swap the pandan extract with ube instead 🙂 This recipe uses mashed purple sweet potato and I haven’t tried out just using ube essence, so that will require some adjustment to other ingredients and I can’t tell you for sure without trying it out myself 🙂
I finally tried your suggestion and it came out to a beautiful dark purple cake when using ube extract. I used 1 and 1/2 tsp. It was so soft, but I overbaked it so it was not as moist as the pandan one I made previously, but it still tasted good. However, the flavor was not as strong and I couldn’t really taste that it was ube so I might add more extract next time. Thanks for the recipe!
THank you for your feedback Joseline. This is also another one I will experiment again pretty soon when I have purple sweet potato to see if I can up the amount of the purple sweet potato. Thanks for trying and for letting me know 🙂
Hey Marvellina…thanks again for patiently answering my query…I was in a huge dilemma whether or not to use baking powder but then I thought a dense and tough cake is worse than having a green cake…so I used baking powder and few drops of lemon juice so my cake was green with streaks of pink and the diced sweet potato pieces were popping out and looking pretty….I was a little sad about the colour but only till I tasted the yummy goodness…my friends were overwhelmed with the spongyness…I’m glad I did not leave out the baking powder…thanks so much for sharing your knowledge
Hi Swathi, actually it’s not a must to use baking powder in chiffon cake, but you have to make sure you whip the egg white meringue properly. Most people use baking powder as an “insurance” for “just in case”. I haven’t really used baking powder in most chiffon cakse unless for certain cases. When you get more comfortable with baking chiffon cake, you can probably try to leave out the baking powder 🙂 I’m glad you guys enjoy the chiffon cake though. I love chiffon cake a lot too! So good on its own and much “healthier” compared to other heavily-frosted cake!
Hi, what a lovely recipe thank you 🙂 do you have the measurements and baking time for a 7 inch chiffon pan?
Hi Sylvia, I have includee measurements and baking tome for 7-inch chiffon pan. Hope it works out for you 🙂
Looks really yummy!! Can I use the regular springform pan instead? If so, do I need to alter the amount for a 10inch cake pan? Thank you.
Hi Wynne, If you use regular springform pan (you have to make sure it has NO non-stick coating or your cake won’t rise), you will need to bake it in a water bath, like making a regular sponge cake. Similar to this https://whattocooktoday.com/taiwanese-castella-cake.html I bake it low and slow at 300 F using a hot water bath for 1 hour 50 minutes or until the cake tester comes out clean, otherwise, you will have cracks on top of the cake. Well, that’s how I bake my sponge cake without a tube pan like chiffon pan. This recipe uses 5 eggs to fit into 8-inch pan, if you use 10 inches, the cake is going to be much shorter. You can 1.6 x the ingredients to fit into 10 inches
Hi. Can I substitute coconut milk with normal milk? Thanks!
Hi Jay, you can use regular milk, it would be less aromatic, but it should work too.
I see. Thanks for the recommendation Marv. 🙂
Hi.. doesn’t the recipe need lemon juice to keep the pretty colour…
Hi Swathi, No, I didn’t use any lemon juice to preserve the color and no issue with the sweet potatoes changing color
Marv, any recommendation for a good chiffon pan?
Hi Anita, the one i use was brought by my mom from Singapore. It’s made with aluminum and with a removable base so perfect for baking this chiffon cake. I’ve seen something very similar from Nordic Ware at Amazon https://www.amazon.com/gp/product/B00008UA41/ref=as_li_tl?ie=UTF8&tag=whtocoto-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B00008UA41&linkId=0dbca0beb6bb6f12db00678d75559e61 This should be a good one to bake chiffon cake
Thanks for replying so promptly…I have one more question…I don’t have aluminium free baking powder…can I use normal one…will it react and change the colour?
Hi Swathi, it might react but also the fact that there are eggs in the recipe, the orange color of the yolk will be more dominant than the purple, so if you really want a beautiful purple color, I suggest adding some ube essence or tiny bit of purple food coloring to preserve that color. Natural color usually is a bit hard to come through, especially with purple sweet potatoes.