Preheat oven 350 degrees. (325 if using a glass pan) Spray a 9-by-5-inch loaf pan with nonstick cooking spray; set aside. Combine dry ingredients in a medium-sized bowl; set aside. Cream butter and sugar in mixer bowl until well blended. Add egg and egg yolk, one at a time, and beat until fluffy. Add extracts; fold in mashed bananas. Stir in dry ingredients gradually, mixing just until combined. Heat peanut butter in microwave just until warm and easily spreadable, about 20 seconds. Pour half of batter in pan. Drop half of peanut butter by spoonfuls on top of batter. Swirl with a knife. Repeat with remaining batter and peanut butter. Bake 60 minutes or until toothpick inserted into the center comes out clean. Cool for 10 minutes; turn out onto cooling wrack to cool completely.