Preheat oven to 350 degrees. Grease a loaf pan.
In a large bowl, cream butter, peanut butter, and sugar until fluffy. Add eggs one at a time, beating them in. Sift in flour, baking powder, baking soda, and salt. Stir until dry ingredients are moistened. Add in bananas.
Gently mix in 1/2 cup of chocolate chips. Pour batter into the bread pan (about 3/4 full). Sprinkle the loaf with the remaining chocolate chips.
Bake 55 to 60 minutes or until a toothpick comes out clean. Cool 10 minutes and remove from pan.