01 -
Preheat oven to 375°F. In a large bowl, combine all-purpose flour, sugar, baking powder, and salt. Stir in milk chocolate chips to coat them evenly with the flour mixture.
02 -
In a separate mixing bowl, whisk together melted butter, vegetable oil, eggs, milk, and vanilla extract until well blended.
03 -
Pour the dry ingredients into the wet ingredients and stir gently just until combined and moist; do not overmix.
04 -
Line a muffin tin with cupcake liners or spray with nonstick cooking spray. Fill each cup about three-quarters full with batter.
05 -
Optional: Top each muffin with two or three additional milk chocolate chips to enhance appearance.
06 -
Bake at 375°F for 15 to 18 minutes until a toothpick inserted in the center comes out clean and muffins spring back when lightly touched.