This chocolate chiffon cake recipe is a decadent twist on the classic chiffon cake. Made with the Thermomix, it is light, fluffy, and has a rich chocolate flavor. The cake is made with a combination of cake flour, sugar, baking powder, salt, vegetable oil, egg yolks, water, and cocoa powder. The egg whites are whipped separately and then folded into the batter to give it its signature airy texture. This cake is perfect for serving with a drizzle of chocolate ganache and fresh berries.