Irish Car Bomb Cupcakes

INGREDIENTS

• :
• 1 cup Guinness stout
• 1 cup unsalted butter, at room temperature
• ¾ cup Dutch-process cocoa powder
• 2 cups all-purpose flour
• 2 cups granulated sugar
• 1½ teaspoons baking soda
• ¾ teaspoons salt
• 2 eggs
• 2/3 cup sour cream
• 8 ounces bittersweet chocolate
• 2/3 cup heavy cream
• 2 tablespoons butter, at room temperature
• 2 teaspoons Irish whiskey
• 2 cups unsalted butter, at room temperature
• 5 cups powdered sugar
• 6 tablespoons Bailey's Irish Cream