I substituted applesauce for all the oil, added a few tblspns each of flax meal and wheat germ for added nutrition (you can't taste it at all!), and halved the choc chips. It made 24 standard sized muffins for me.
My 1 year old and 3 year old both loved them! Super moist! A few people commented on the "baking powder" taste - whenever I mix my dry ingredients, I mix thoroughly with a whisk to get everything combined, then pour through my sifter - you will never ever have that problem again.
(tip - if adding wheat germ/flax/oatmeal or any other whole grain to make your baked goods more nutritious, make sure to add it to the wet ingredients - don't put it through the sifter, or you'll find some grains get stuck and come find their way out in your next batch of frosting, no matter how well you clean it!)