Preheat to 375℉, grease a mini muffin tin or line with paper liners. Set aside.
In a bowl, mix the flour, baking powder, baking soda, salt, and cinnamon. Set aside.
1½ cups all-purpose flour, 1½ tsp baking powder, ¼ tsp baking soda, ¼ tsp salt, ½ tsp cinnamon
In a separate large bowl, whisk together the melted butter, oil, sugar, egg, vanilla, milk, and greek yogurt.
2 tbsp unsalted butter, 3 tbsp vegetable oil, ½ cup granulated sugar, 1 large egg, ¾ tsp vanilla extract, ½ cup milk, 3 tbsp plain greek yogurt
Use a rubber spatula to gently fold in the dry ingredients until just mixed, be careful not to over mix. Fold in the chocolate chips.
½ cup mini chocolate chips
Fill each mini muffin tin about ¾ of the way. Bake for 9-11 minutes, or until a toothpick comes out clean.