MY rice flour cakes always rise nicely, resulting in a fluffy cake. When I add pieces of fruit (mostly fresh) like cherries in a chocolate cake, apples in an apple cake or shredded sweet potato, the cake rises just a little bit. There are some microscopic air bubbles, but it is basically one thick clump of (nevertheless soft) dough. It isn't fluffy or has air bubbles at all. Why is this, how can I improve it?
This is the basic recipe I use: rice flour, eggs, and baking powder (bicarb + acid). Then there are some varying things regarding taste, like salt, sugar, chocolate etc. Note that there isn't any milk.