Chocolate Stout Cupcakes With Vanilla Stout Buttercream

Ingredients

• 12 tablespoons (1 1/2 sticks) unsalted butter
• 1/2 cup cocoa powder
• 3/4 cup dark stout, such as guinness, poured and settled before you measure
• 2 large eggs
• 1/2 cup full-fat sour cream
• 1 1/4 cups unbleached all-purpose flour
• 1 1/4 cups sugar
• 1 teaspoon baking soda
• 1/4 teaspoon salt
• 8 tablespoons (1 stick) unsalted butter, softened
• 3 cups confectioners’ sugar, sifted through a strainer
• 3 tablespoons dark stout, such as guinness, poured and settled before you measure
• 1/4 teaspoon vanilla extract
• pinch salt
• 3/4 cup crushed chocolate-covered pretzels, (optional)