Preheat your oven to 425 degrees and prepare your muffin tin with liners, or grease it well with non-stick cooking spray.
Dry Ingredients: In a large bowl, combine the flour, baking powder, baking soda, salt, and chocolate chips and set it aside.
Wet ingredients: In another bowl, mix together the melted butter, sugar, eggs, buttermilk, and vanilla.
Combine: Add the dry ingredients to the wet mixture and use a spatula to gently fold the mixture together, just until combined. Be careful not to over-mix the batter.
Bake: Divide the batter evenly among well-greased muffin cups (they will be full to the top). Bake at 425 degrees F for 5 minutes. Then, reduce the oven temperature to 375 degrees F and continue baking for 10-15 more minutes or until a toothpick inserted into the center of a muffin comes out clean. Don't over-bake them or they will be dry.
Remove muffins to a wire cooling rack to cool.
Video
Notes
Storing Instructions: Keep cooled muffins in an airtight container or bag with a paper towel underneath and top so they don't get soggy.Freezing Instructions: Place cooled muffins in an airtight container or bag in the freezer for up to 3 months. Thaw on your counter or warm for a few seconds in the microwave.