Please can anyone offer any advise or suggestions? I have been baking for quite a few years now but just recently my sponge cakes have had a dense rubbery texture.  I have never had this problem before and I really don't know what im doing wrong now.  I have tried changing my flour, I have replaced my scales, I have tried baking at a different temperature, using a heating rod in the middle and ive also been making sure that I cream my butter and sugar together enough. Ive even tried a different recipe. I just don't know what im doing wrong.  I don't seem to have a problem when baking the cakes in two halves, its mainly when I am baking a deep cake. Im so fed up of wasting ingredients and stressing about how my cakes will turn out, any advice would be brilliant, thank you.