Preheat oven to 350°. Line the muffin tin with paper liners.
Using either an electric hand mixer or stand mixer, cream together the butter, sugar, vanilla and eggs.
Add the flour, baking powder and salt to the bowl. Slowly start to incorporate the dry ingredients.As the dry ingredients are being mixed into the butter mixture, slowly pour the milk into the batter.
Once all of the ingredients are incorporated, turn the speed up and whip the batter until extremely smooth.
Fold in the mini chocolate chips.
Divide the batter among the muffin tins.
Bake at 350°. For the muffins, bake for 20-25 minutes, it should pass the toothpick test before taking out of the oven.