I just popped these out of the muffin tins and they are superb! I filled my cups to just at the line and still had enough batter to fill a 12 cup mini muffin tin, as well (baked for half the time). The minis are adorable!
I did some substitutions: I used 1/3 cup applesauce and left out the oil, I used all whole wheat flour, I added 1/2 cup black walnut pieces to the batter with the dark chocolate chunks as well as chopping up another 1/2 cup to top the muffins with, and instead of using buttermilk I used lowfat buttermilk powder, and for the liquid I used whey I drained off some plain, nonfat yogurt. I like to drain it to make the yogurt thicker and the liquid is great in baked goods such as this. My kiddo swooned at first bite, this is a keeper!