Preheat oven to 350°F. Line your 9x5 loaf pan with parchment paper, greasing the areas that are not covered with the paper. If not using parchment paper, generously grease the loaf pan.
Mix together the flour, baking soda, baking powder, salt, and cinnamon in a bowl. Set aside.
2 cups all-purpose flour, 1 teaspoon baking soda, 1 teaspoon baking powder, 1 teaspoon salt, 1 teaspoon ground cinnamon
In a mixing bowl, beat the butter and sugar together until light and fluffy.
1 cup brown sugar, ½ cup butter
Add in the eggs one at a time, beating after each one is added.
2 eggs
Add in the mashed banana, milk, and vanilla extract.
3 ripe bananas, 1 teaspoon vanilla extract, 1 tablespoon milk
Combine the dry ingredients with the wet ingredients. Mix just until combined - then mix in the chocolate chips.
¾ cup semisweet chocolate chips
Pour the batter into the prepared pan.
Bake until toothpick comes out clean, about 60 minutes. Cool slightly before serving.