ok, i've tried several different recipes for banana bread and pumpkin bread and it seems like no matter what i do, it doesn't come out fully cooked (it's dense halfway down when sliced, not light and spongy like it's supposed to be). i have an oven thermometer to check the temp of the oven, and i leave the batter in there long enough (i even left my banana bread to bake for a half hour longer once - it didn't make a difference). normally i am a good baker but i can't seem to get this stuff right. what could i be doing wrong? it's driving me nuts!!! help.