Mix all the dry ingredients in a mixing bowl and set aside (1 ½ cup all-purpose flour, 1 tsp baking soda, 1 tsp baking powder, ½ tsp salt, and 1 tsp cinnamon).
In a separate large mixing bowl, place 3 well ripe bananas. Using a fork, smash them until even consistency. Though, I like to leave a few larger chunks to have more texture.
Add the rest of the ingredients (⅓ cup melted coconut oil, ½ cup maple syrup, 1 egg, 1 tsp vanilla extract, and 3 tbsp milk) and whisk well.
Add dry ingredients to the wet ingredients. Using a spatula, fold it in until combined. Try not to overmix the batter!
Add 1 cup chocolate chips and fold them in.
Using a large ice cream scoop (3 tablespoons), scoop the batter into the muffin tin (lined with muffin liners or just greased). You should have exactly 12 muffins.
Bake at 350°F for about 20-25 minutes or until a toothpick inserted in the center comes out clean.
Take them out of the oven and let them sit in a muffin tin for 5 minutes, then transfer to a wire rack.