Chocolate-Chocolate Chip Muffins
Source:  slightly adapted from Brown-Eyed Baker

Yield: 12 muffins
Ingredients:
¾ stick (6 tablespoons) unsalted butter
2 ounces bittersweet chocolate, coarsely chopped
2 cups all-purpose flour
2/3 cup granulated sugar
1/3 cup unsweetened cocoa powder, sifted
1 tablespoon baking powder
½ teaspoon baking soda
½ teaspoon salt
1¼ cups buttermilk
1 large egg
1 teaspoon pure vanilla extract
1 cup semi-sweet chocolate chips


Directions:
1. Center a rack in the oven and preheat the oven to 375 degrees F. Butter or spray the 12 molds in a regular-size muffin pan or fit with paper muffin cups. Place the muffin pan on a baking sheet.
2. Melt the butter and the chopped chocolate together in a bowl over a saucepan of simmering water. Remove from the heat.
3. In a large bowl, whisk together the flour, sugar, cocoa, baking powder, baking soda and salt. In a large glass measuring cup or another bowl, whisk the buttermilk, egg and vanilla extract together until well combined. Pour the liquid ingredients and the melted butter and chocolate over the dry ingredients and, with the whisk or a rubber spatula, gently but quickly stir to blend. Do not overmix the batter. Stir in the chocolate chips. Divide the batter evenly among the muffin cups.
4. Bake for about 20 minutes, or until a toothpick inserted into the center of the muffins comes out clean. Transfer the pan to a rack and cool for 5 minutes before carefully removing each muffin from its mold.