Preheat oven to 400 degrees. Place mini cupcake paper liners in baking pan and set aside.
In a medium bowl, whisk together flour, baking powder, baking soda, salt and cinnamon, and set aside.
2 1/4 cups flour, 2 tsp baking powder, 1/2 tsp baking soda, 1/2 tsp salt, 1/2 tsp ground cinnamon
In a large bowl, cream the butter and sugar until light and fluffy.
1/2 cup butter, 1 cup sugar
Add eggs, vanilla and sour cream and mix well.
2 eggs, 2 tsp vanilla extract, 1/4 cup sour cream
Add the flour mixture and the buttermilk alternating and ending with the buttermilk. Break up any small lumps as you go.
1 cup buttermilk
Using a rubber spatula, fold in the chocolate chips reserving some to sprinkle on top.
1 cup mini chocolate chips
Using a small cookie scoop, add the batter to the prepared mini muffin pan and bake for 10-12 minutes.
Sprinkle the additional chocolate chips on top, then allow muffins to cool in pan for 10 minutes before removing to a wire rack to finish cooling.
Serve warm and enjoy!