70grgranulated sugaramount also depends on how ripe/sweet the bananas you use
1tsplemon juice/vinegar
Instructions
Prepare the cake batter:
Preheat oven at 330 F (165 C). My oven is conventional with bottom heat only. If you have a convection oven, I suggest lowering the temperature by 25 F (15 C). Mash bananas together with coconut sugar. Add yolks and oil and whisk to combine. Sift in cake flour, baking powder, and salt and whisk to combine. There might be some lumps from the bananas, that's ok
Make the meringue:
Place the egg whites in a mixing bowl. Whisk over medium speed using a whisk attachment for one minute until foamy and then add vinegar and whisk for another minute. Increase the speed to high and add sugar in 3 batches and beat until the meringue is glossy and stiff. You can always stop halfway and check. When you lift the meringue up with the whisk attachment, the meringue should stand up stiff and just bent slightly at the tip but not moving. If you turn the bowl upside down, the meringue won't drip. This is a stiff peak and you can stop whipping. Do not overwhip the meringue or it's going to break
Fold meringue into the cake batter:
Scoop 1/3 of the meringue into the cake batter. Use a whisk or a rubber spatula to gently fold the meringue into the cake batter. Cut through the middle and fold over. Then the next 1/3 and do the same until all the meringue are incorporated into the cake batter and continue with the last 1/3. The batter should be fluffy and voluminous at this point
Divide the batter into 2 and sift in 1 Tbsp of cocoa powder and mix gently until incorporated. It's important to sift in the cocoa powder to minimize lump. Very gently fold to mix the cocoa powder into the batter
Pour 1/3 of white batter into an UNGREASED chiffon tube pan, then alternate with the cocoa batter and so on. Your tube pan should not have a non-stick coating too or it won't rise high. The batter needs to cling to the pan to rise up tall
Bang the cake pan on the counter about 3-4 times to pop large air bubbles inside the cake batter
Baking:
Place the cake pan in the middle rack and bake for 50 minutes and then lower temperature to 300 F and bake for another 10 minutes or until a cake tester inserted into the cake comes out clean
Cooling down:
Remove from the oven and drop the cake pan from about 6 inches height on the countertop. This helps to minimize shrinkage. Immediately turn the cake pan upside down and let it cools down this way for the next 1 hour or so
Unmould the cake when it has cooled down completely. Run an offset spatula around the edge and the middle of the tube to loosen the edge. Push the bottom up to release the cake. Use an offset spatula to loosen the bottom of the cake and turn the cake over to a serving platter. The cake tastes the best the next day after the flavor has a chance to develop
Storage:
If you can wait until the next day to serve, cover the whole cake with a cling wrap once it has cooled down completely and it can be kept at room temperature for 3 days
Video
Notes
Recipe adjustment for different tube size:
For 6 inch tube: use 2 eggs and multiply 0.4 the rest of the ingredients. Bake for 35-40 minutes , then lower temperature to 300 F (150 C) for 5-10 minutes
For 7 inch tube: use 3 eggs and multiply 0.6 the rest of the ingredients. Bake for 40-45 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 1.6 the rest of the ingredients. Bake for 50-55 minutes, then lower temperature to 300 F (150 C) for 10-15 minutes