Xavier is not a kale-eating kid. I think you have to live in Brooklyn to have one of those. He will, however, eat a muffin in any form so sneaking vegetables into muffins is one of my many clever parenting strategies. My other ones involve TV and sugar.
These muffins from the Whole Foods site use 100% whole wheat flour, 1/4 cup of ground flaxseed, pumpkin, yogurt (I used full-fat) and molasses among other things. The recipe skips butter entirely...although you can see in the photo how Ryan made up for that 'flaw.'
For the hell of it I just googled kale muffins. They do exist. Yuck!