Guinness Cupcakes with ganache filling and Baileys buttercream icing

Makes 20 to 24 cupcakes.
For the Guinness Chocolate Cupcakes
1 cup Guinness stout beer
1 cup (2 sticks) unsalted butter
3/4 cup unsweetened cocoa powder
2 cups all-purpose flour
2 cups dark brown sugar
1 1/2 teaspoons baking soda
3/4 teaspoon salt
2 eggs
2/3 cup sour cream
1 teaspoon extract vanilla
Ganache filling
8 ounces bittersweet chocolate
2/3 cup heavy cream
2 tablespoon butter, room temperature
Baileys Frosting
5 1/2 to 6 cups confectioners sugar
2 sticks (1 cup) unsalted butter, room temperature
6 to 8 tablespoons Baileys
-Special equipment: Bismarck Round Decorating Tip 230 and a pipping bag for filling the cupcake.

Cupcakes directions
Preheat oven to 350F.
Line 24 cupcake cups with liners. Bring 1 cup stout and 1 cup butter to simmer in a saucepan. Add cocoa powder and whisk until mixture is smooth. Cool slightly.
Whisk flour, sugar, baking soda, and salt in a bowl. Beat eggs and sour cream in bowl to blend. Add stout-chocolate mixture to egg mixture and combine. Add flour mixture and beat to combine.  Fill cupcake liners with dough, 2/3 to 3/4 of the way. Bake about 18 minutes. Cool cupcakes completely.
Filling directions
Put chocolate in a heatproof bowl. Heat the cream until simmering and pour it over the chocolate and stir until smooth. Add the butter and stir until combined. Let it cool.
Prepare a decorating bag with your ganache and Round Decorating Tip 230; insert tip in top center of cupcake go most of the way down the cupcake but not cut through the bottom (aim for 2/3 of the way) and squeeze out a small amount of filling.
Frosting directions
Whip the butter until light and fluffy. Slowly add the powdered sugar while beating. When the frosting looks thick enough to spread, drizzle in the Baileys cream and beat until combined.
 Ice and decorate the cupcakes.