Preheat oven to 375 F.
Place cupcake liners into the cupcake tray. Set aside.
In a bowl, sift together flour, baking powder, and salt. Set aside.
In a large bowl, combine vegetable oil and sugar
Mix in egg and sour cream.
Stir in vanilla extract.
Combine dry ingredients into the wet ingredients, alternating with the buttermilk. (Just until the flour is incorporated. Do not over stir or muffins won't be fluffy)
Fold in chocolate chips.
Pour batter evenly into prepared muffin tin.
Sprinkle a few additional chocolate chips on top of batter.
Bake for 18-20 minutes. (check on them at the 16-minute mark)
Remove from oven and let cool in pan for a few minutes,( muffins will continue cooking as they cool).
Remove muffins and place on a cooling rack to finish cooling.
Serve warm or room temperature.