I baked cupcakes with fruit (blueberries, pineapple, mango) and it came too moist and not fluffy. When I took it out of the oven it became a flat on top. I'm following a basic recipe and I add fresh fruit. Should I be adding it frozen fruit? When I made the blueberry cupcakes, it was a little oily on the bottom of the wrapper. My banana cupcakes came out perfect, as well as the strawberry. I used frozen strawberries though. The banana was not frozen. I don't know what I am doing wrong and I need help.
when I use fruit in cupcakes I always use a little bit of flour to coat them.