Preheat the oven to 375°F and line a muffin tin with paper liners or lightly grease with nonstick spray.
In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt until well combined.
In a separate bowl, cream the softened butter with a hand mixer or stand mixer until smooth. Add the eggs one at a time, mixing well after each addition, then stir in the milk and vanilla extract.
Gradually add the dry ingredients to the wet ingredients, mixing just until no dry streaks remain. Fold in the mini chocolate chips with a spatula.
Divide the batter evenly among the muffin cups, filling each about 3/4 full.
Bake for 18-20 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Let the muffins cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely.
Once cooled, dust the tops of the muffins with powdered sugar for a festive finish.