Add the flour, sugar, and baking powder to a large mixing bowl.
In a separate mixing bowl, combine the eggs, mashed bananas, melted butter, milk, sour cream, and vanilla extract.
Stir the wet ingredients into the dry ingredients until moistened. Do not over mix.
In a small bowl, combine the softened cream cheese, sugar, and cinnamon with a hand mixer or with a spoon.
Add the cream cheese mixture to a sandwich size ziplock bag and set aside.
Place baking liners in a muffin pan and add 2 tablespoons of batter to each cup. (I use a 2 tablespoon cookie scoop)
Snip off the corner of the ziplock bag and squeeze approximately 1 tablespoon of the cream cheese mixture into the center of each muffin.
Top each muffin with 2 more tablespoons of batter.
Bake the muffins at 400 degrees for 18-22 minutes or until a toothpick comes out clean.
Let the muffins cool in the pan for 5 minutes before serving.