Preheat the oven to 350°F. Line a 12 cupcake pan with cupcake liners. Sift flour, baking powder, baking soda, salt and cinnamon together in a bowl and set aside.
In a large mixing bowl, add in butter, granulated sugar and brown sugar. With the paddle attachment, start beating on medium for about 2-3 minutes (scrape the bowl with a spatula half way through) until light and fluffy.
Add the eggs one at a time, mixing well after each addition (about 30 seconds). Scrape the sides of bowl to make sure everything is combined. Add vanilla extract and mix.
Add in mashed bananas and mix until combined.
Mix in the dry ingredients in 3 parts, alternating with milk, beating well after each addition. This means, adding one third of the dry ingredients, mixing a little bit until incorporated, then adding half of the milk and mixing until combined. Then, add another one third of the dry ingredients, mix, add the rest of the milk, mix, and finally add the last part of the dry ingredients. So, we start and finish with the dry ingredients.
Fold in the chocolate chips.
Fill each cupcake pan two thirds of the way and bake in the preheated oven for 15-20 minutes or until a toothpick comes out clean.
Let them cool down completely before frosting.