Preheat the oven to 400F.
Either grease the cups for a mini muffin pan with cooking spray or place mini cupcake paper liners in each cup of a mini muffin tin. Set the pan aside.
In a medium bowl, blend together the dry ingredients of flour, baking powder, baking soda, salt, and cinnamon.
In a large bowl, cream together the butter and sugar until fluffy. Stir in the eggs, vanilla.
Add sour cream.
Alternate adding the flour mixture and the buttermilk to the bowl with the butter and sugar mix. Stir until blended and break up any lumps, but do not over-mix.
Fold in the chocolate chips, but hold back a tiny bit to sprinkle on top.
Once the mini chocolate chips are folded in, scoop batter into the prepared mini muffin pan with a rubber spatula.
Sprinkle the top of each muffin tin cup with the remaining chocolate chips. Optional: Sprinkle each muffin with a little coarse sugar.
Bake for 10-12 minutes or until a toothpick inserted in the center of a muffin comes out clean and the tops of the muffins are lightly browned.
Cool for 10 minutes in the pan and then transfer to a wire rack. Serve warm or store in an airtight container once fully cooled.