Grease and flour two 7½" x 3¾" x 2¼" or one 9"x5" loaf pan. Preheat oven to 350˚F (180°C).
Combine all purpose flour, baking powder, baking soda, cinnamon, and salt in a medium sized bowl.
Peel and mash bananas with a fork in a bowl.
Cream butter, cream cheese, and sugar in a large bowl until light and fluffy, about 2 minutes.
Beat in eggs and vanilla extract until combined.
Add flour mixture, mashed bananas, and buttermilk. Stir until just combined.
Pour batter into prepared pan(s).
Bake for 50 minutes (if using two 7½" x 3¾" x 2¼" loaf pans) to 1 hour (if using one 9"x5" loaf pan), or until wooden pick inserted in the center comes out clean. If the top is browning too quickly, place an aluminum foil tent over bread.
Cool in pan for 10 minutes. Remove and cool completely on wire rack.