Guinness Chocolate Cupcakes with Mocha Guinness Buttercream

Bahan-bahan (16 porsi)

• one (11.2–12-ounce (330–355ml) bottle Guinness Draught Stout beer
• 1 cup (125g) all-purpose flour (spooned & leveled)
• 1/2 cup (41g) unsweetened natural cocoa powder
• 1 and 1/2 teaspoons espresso powder
• 3/4 teaspoon baking soda
• 1/4 teaspoon salt
• 1/2 cup + 1 Tablespoon (135ml) vegetable or canola oil
• 1 cup (200g) packed light or dark brown sugar
• 2 large eggs, at room temperature*
• 3/4 cup (180g) full-fat sour cream, at room temperature*
• 2 teaspoons pure vanilla extract
• 2 Tablespoons (30g/ml) reduced Guinness from step 1
• 2 teaspoons espresso powder
• 1 and 1/4 cups (282g) unsalted butter, softened to room temperature
• 4 and 1/2 cups (550g) confectioners’ sugar
• 1 Tablespoon (5g) unsweetened natural cocoa powder
• 1 Tablespoon (15g/ml) milk
• 1 teaspoon pure vanilla extract
• pinch of salt, to taste