Chocolate Chip Muffins

Bahan-bahan (1 porsi)

• 2 cups all-purpose flour, (spooned into measuring cup and leveled-off)
• 1 teaspoon baking powder
• ½ teaspoon baking soda
• Heaping ½ teaspoon salt
• 1/2 cup (1 stick) unsalted butter, melted and cooled slightly
• ½ cup granulated sugar
• ½ cup (packed) light brown sugar
• 1½ teaspoons vanilla extract
• 2 large eggs
• 1 cup sour cream
• 2/3 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)