Chocolate Chip Muffins

Name: Chocolate Chip Muffins
Prep time: 15 min
Cook time: 20 min
Total time: 35 min
Yield: 12 muffins
Ingredients: 2 cups all-purpose flour, spooned into measuring cup and leveled-off; 1 teaspoon baking powder; ½ teaspoon baking soda; Heaping ½ teaspoon salt; 1 stick (½ cup) unsalted butter, melted; ½ cup granulated sugar; ½ cup packed light brown sugar; 1½ teaspoons vanilla extract; 2 large eggs; 1 cup sour cream; ⅔ cup mini semi-sweet chocolate chips, plus about 3 tablespoons more for sprinkling on top; About 1½ tablespoons coarse sugar, such as turbinado or sanding sugar, for sprinkling on top