Preheat oven to 325 degrees F (165 degrees C). Grease a 9x5-inch loaf pan. Prepare 3 bowls (two medium one large) to mix ingredients.

In a a medium bowl, mix flour, baking powder, baking soda, and salt.

In another medium bowl, mash the bananas until desired consistency then add the milk, vanilla, and cinnamon.

In the larger bowl, beat room temp butter and sugar until light and fluffy. Add eggs to butter mixture, one at a time, beating well after each addition.

Stir the banana mixture into butter mixture. Then, stir in dry mixture until fully blended.

Fold in peanut butter cups until combined.

Once ready, pour the batter into prepared loaf pan.

Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 70 minutes. Cool in the pan for 10 minutes before removing to cool completely on a wire rack before slicing.