Whisking butter and sugar together is one essential tip to make the cake spongy, fluffy and moist. Whisk butter and sugar for long until the mixture becomes pale yellow and fluffy because of incorporation of air.
Why is my sponge cake not light and fluffy?
If your sponge has come out too heavy or dense but cooked through, this could be due to under-mixing. Mixing is an important step in incorporating lots of air so that the sponge becomes light and fluffy. It could also be due to the fact that there werent enough raising agents used.
Why does a cake become fluffy after baking?
Baking powder is added to the flour while preparing the dough for the cakes. When baking powder mixes with water, then the sodium hydrogen carbonate reacts with tartaric acid to evolve carbon dioxide gas which gets trapped in the wet dough and bubbles out slowly making the cake to rise and hence soft and spongy.