Chocolate Chip Muffins

I found this recipe on the internet when I was looking for a recipe for muffins that used white chips, and I used this recipe, substituting white chips for the chocolate chips. I have never actually made this recipe with chocolate chips, but here is as it was originally published:

2 cups all-purpose flour
1/3 cup light-brown sugar, packed
1/3 cup sugar
2 teaspoons baking powder
� teaspoon salt
2/3 cup milk
� cup butter, melted and cooled
2 eggs, lightly beaten
1 teaspoon vanilla
1 12 oz. package jumbo or regular milk chocolate chips (or white chips)
(optional) � cup walnuts or pecans, chopped

Preheat oven to 400�F. Grease twelve muffin cups. In a large bowl, stir together flour, sugars, baking powder, and salt. In another bowl, stir together milk eggs, butter, and vanilla until blended. Make a well in center of dry ingredients; add milk mixture and stir just to combine. Stir in chocolate chips (and nuts). Spoon batter into prepared muffin cups; bake 15-20 minutes, or until cake tester (toothpick) inserted in center of one muffin comes out clean. Remove muffin tin to wire rack; cool 5 minutes and remove from tins to finish cooling. Make 12 muffins.