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 oven to 330 F (165 C). My oven is a conventional oven with bottom heat only, no fan. Place the oven rack 3rd from the top. You may need to lower your temperature by about 15 degrees if your oven uses top and bottom heat
Prepare the yolk batter:
Separate the yolks from the whites while they are still cold. They are easier to separate. Then let them come to room temperature
Pour out the liquid from the tofu. Put the tofu in a blender and puree until smooth
Whisk the egg yolks, tofu, sugar, cooking oil, and vanilla extract. Sift in the cake flour and salt into the batter. Whisk in a zig zag motion to mix into a smooth batter. Set aside
Prepare the meringue:
Place the egg whites in a clean mixing bowl. I use a stand mixer with a whisk attachment. 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 until frothy, add cream of tartar or lemon juice/vinegar and whip until it turns whitish. Gradually add the sugar as you beat, in 3 batches. I beat them at medium speed (speed 6 on Kitchen Aid) until you reach a stiff peak but still have a slight bent on the tip. I recommend stopping several times to check on the consistency. When you lift up the whisk, it should hold its shape firmly but has a slight bent on the tip. Stop once you reach this stiff peak. If you beat until the meringue clumps in one big lump to the whisk, you know you've gone too far beating the meringue
Fold meringue into the yolk batter:
Gently fold 1/3 of the meringue into the thick batter. Using a whisk, using a cutting motion and fold over to mix. Repeat this motion several rounds. Continue on with the second 1/3 of the meringue again to mix. For the last 1/3 of the meringue, use a rubber spatula instead to ensure you get all the batter at the bottom of the bowl mixed in as well. Use a cut down in the middle and fold over motion to fold gently but quickly. Make sure you don't see any more white meringue. The mixture should be fluffy and voluminous.
Pour the batter into an UNGREASED chiffon cake pan. Use a rubber spatula to smooth the surface. Gently drop the cake pan from about 10 cm height on the counter 2-3 times. Use a skewer to draw a zig zag to pop bubbles inside the cake batter.
Pop into the oven and let it bake at 330 F for 50 minutes. Check for doneness by inserting a cake tester. If it comes out clean and the top is springy and dry to touch, you can remove it from the oven. If not, reduce the heat to 300 F (150 C) and bake for another 10-15 minutes. The time is just for reference
Don't be alarm if your cake has some cracks on top. What you are looking at will become the bottom of your cake. I know many people mind it a lot and make a big fuss when the top of the chiffon cake cracks, but actually it's not a flaw.
Once out of the oven, drop the cake pan from about 10 cm height on the counter several times to prevent shrinkage. Then carefully invert the pan upside down immediately. Your chiffon pan may have the little stands for you to invert, but I find it not high enough. I use a glass jar and set the inverted pan on top of the jar and let it cool down completely. 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 a spatula knife to run through the edge and the outer center of the tube to help release the cake. Gently push the base to lift the cake out. Use the knife again to run through the base of the pan and then carefully release the cake
The cake can be stored at room temperature for about 3 days. Make sure to store it in air-tight container
Recipe adjustment for different tube size:
For 7 inch tube: use 4 eggs and multiply 1.3 the rest of the ingredients. Bake for 50-55 minutes , then lower temperature to 300 F (150 C) for 5-10 minutes
For 8 inch tube: use 5 eggs and multiply 1.7 the rest of the ingredients. Bake for 55-60 minutes, then lower temperature to 300 F (150 C) for 5-10 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 2.7 the rest of the ingredients. Bake for 60-65 minutes, then lower temperature to 300 F (150 C) for 5-10 minutes