Preheat the oven to 350 degrees. Grease an 8x10 or 9" square pan with butter. In a large glass bowl, heat the peanut butter and the honey in the microwave for about 30 seconds. Stir and heat an additional 15-20 seconds, as needed, to liquify the peanut butter. Stir in the mashed bananas, sour cream and eggs. Add all remaining ingredients and stir again. Pour into the greased pan. Bake for 35 minutes, until a knife comes out mostly clean. Let cool 5-10 minutes before serving.