- 1/4 cup (2 ounces) red food coloring
- 3 1/2 tablespoons high-quality unsweetened cocoa powder
- 1 cup (2 sticks) unsalted butter at room temperature
- 1 3/4 cups sugar
- 2 large eggs
- 2 cups cake flour
- 1 1/2 cups all-purpose flour
- 1 teaspoon kosher salt
- 1 teaspoon baking soda
- 2 teaspoons vanilla extract
- 1 cup buttermilk
- 1 cup sour cream
- 1 tablespoon distilled white vinegar
- 1 cup (2 sticks) unsalted butter at room temperature
- 1 cup (8 ounces) cream cheese at room temperature
- 2 cups powdered sugar
- 1 teaspoon vanilla extract
- Pinch of kosher salt
- 1 cup (8 ounces) mascarpone (Italian cream cheese, available at most grocery stores)
- 1 teaspoon vanilla or mint extract
- Crushed peppermint candy for garnish (optional)
- Preheat the oven to 350°F. Grease jumbo muffin cups (3 1/2 inches in diameter and 2 inches deep) with butter or cooking spray, and lightly flour them, knocking out the excess flour, or line them with baking papers.
- In a small bowl, stir the food coloring and cocoa powder together to make a smooth paste. Set aside. Using an electric mixer fitted with the paddle attachment, cream the butter and the sugar on medium-high speed until light and fluffy, about 2 minutes. Add the eggs, one at a time, beating after each addition, then add the cocoa paste while continuing to beat. Reduce the mixer speed to medium and beat the batter for about 4 minutes. In a medium bowl, sift together the cake flour, all-purpose flour, salt, and baking soda. Stir the vanilla into the buttermilk (this can be done in the measuring cup). Add the flour mixture in 3 increments alternately with the buttermilk in 2 increments, starting and ending with the flour. Beat on medium speed just until the ingredients are combined. Add the sour cream and vinegar and beat on low speed until combined.
- Fill the muffin cups three-fourths full with batter. Bake for 25 to 35 minutes, just until the cupcakes feel firm to the touch and a toothpick inserted in the center comes out clean. Do not overbake, or the cupcakes will dry out. Remove from the oven and let cool in the pans for 5 minutes, then unmold onto a wire rack and let cool completely before frosting.
- To make the icing: In the large bowl of an electric mixer fitted with the paddle attachment, beat the butter, cream cheese, and powdered sugar on medium-high speed until light and fluffy. Beat in the mascarpone on very low speed until just combined. (Be careful; once you've added the mascarpone, excessive beating can make the frosting curdle.) Stir in the vanilla or mint extract.
- Frost the top of each muffin with the icing. Sprinkle the crushed peppermint candy, if using, evenly on the cupcakes.