Chocolate Chip Banana Peanut Butter Muffins

I used the banana butterscotch chip muffin recipe from Nigella Lawson's "Nigella Express" cookbook.  I replaced the butterscotch chips with chocolate, the sugar with cane sugar, and the white flour with a mixture of whole wheat and kamut flour and ground flax seeds.  Then I put a dollop of all-natuaral peanut butter in the centre of each one.  There was one day when I ate four in one sitting.