Preheat oven to 375 degrees F and line a muffin pan with paper liners
In a medium bowl combine the flour, baking powder, baking soda, salt and cinnamon; set aside
In another large bowl mash the bananas until creamy, add in the light brown sugar, egg, melted butter, sour cream and vanilla extract; whisk until fully combined
Add the dry ingredients to the wet ingredients and whisk until all ingredients are combined and batter is smooth
Fold the chopped pecans into the banana muffin batter
Scoop the muffins batter into the lined muffin pan until they are each ¾ full
Top each muffin batter with a sprinkle of the Brown Sugar Pecan Topping
Bake for 17-18 minutes or until a cake tester comes out clean
Remove the muffins from the oven and allow them to cool in the muffin pan for 5-10 minutes before serving
If you are not enjoying immediately, allow the muffins to cool completely before storing them in an airtight container