I've been making muffins for the past two weeks or so, just to hide fruits and veggies for Garrett. We've tried a few different combinations, just replacing the oil with baby food purees. I've also chopped up some apples into some of them.
It's working. He'll eat any muffin I throw in front of him, with the exception of pumpkin. Which is just fine, I'll keep my pumpkin puree for myself. :)