Mudslide Cupcakes - Cupcake Fanatic

Ingredients

• 3 eggs, separated and at room temperature
• 3/4 cup granulated sugar
• 1/2 cup (1 stick) unsalted butter, room temperature
• 1 cup light brown sugar, packed
• 2 and 1/4 cups all-purpose flour
• 1/2 cup unsweetened cocoa powder
• 1 and 1/2 teaspoons baking soda
• 3/4 cup strong cold coffee
• 3/4 cup Kahlua
• 6 tablespoons unsalted butter, room temperature
• 3 cups (or more, if needed) powdered sugar
• 3 tablespoons unsweetened cocoa powder
• 4 tablespoons Kahlua
• 3 tablespoons hot coffee
• 16 tablespoons (2 sticks) unsalted butter, room temperature
• 3 cups powdered sugar
• 2 teaspoons vanilla extract
• 4 tablespoons Bailey's Irish Cream
• 4 ounces bittersweet chocolate, shaved in curls