Brownie Cupcakes with Rich Chocolate Buttercream Frosting - Bake it Good

Ingredients

• 1 Box Brownie Mix
• ½ cup (60g) All Purpose Flour
• ½ cup (100g) Granulated Sugar
• 1½ teaspoons (6g) Baking Powder
• 2½ Tablespoons (15g) Unsweetened Cocoa Powder
• 1 stick unsalted butter, melted (113g/½ cup)
• 1 cup sour cream (full fat)
• ½ cup hot coffee or hot water (e.g., instant espresso dissolved in hot water)
• 3 large eggs
• 1 Fudge Packet (if included with brownie mix)
• 1½ sticks unsalted butter, softened (170g, do not microwave)
• 2½ cups powdered sugar
• ½ cup unsweetened cocoa powder, sifted (35g)
• 1-2 tablespoons milk, plus additional if needed
• 1 teaspoon vanilla extract (4g)
• 1 teaspoon salt (6g)