Preheat oven to 350˚F and lightly grease two mini loaf pans or one 9 x 5 loaf pan
In a separate bowl, beat the butter, oil and sugar until light and creamy
Beat in the egg, then stir in the vanilla, banana and sour cream
Gently mix the dry ingredients and chocolate chips until well incorporated
Pour the batter into the pans and bake for 45 to 60 minutes-bake for a shorter time for two mini loaves and longer for the large loaf, until a toothpick comes out clean
Remove the breads from the oven and allow to rest in the pans for 10 minutes
Turn the bread out onto a rack to cool completely
Yield: Two mini loaves or one 9 x 5 loaf
