- 2 1/2 cups all-purpose flour
- 2/3 cup unsweetened cocoa powder
- 1 1/4 teaspoons baking soda
- 1 teaspoon salt
- 1/4 teaspoon baking powder
- 1 2/3 cups white sugar
- 2/3 cup butter, softened
- 1 1/4 cups water
- 1 teaspoon vanilla extract
- 2 eggs
- 2 cups chocolate chips (optional)
- 2 tablespoons all-purpose flour (optional)
- 1 cup butter, softened
- 1/4 cup Irish cream liqueur (such as Baileys®)
- 2 teaspoons vanilla extract
- 3 drops green food coloring (optional)
- 3 cups confectioners' sugar, or more as needed
- Preheat oven to 350 degrees F (175 degrees C).
- Line 24 muffin cups with paper liners.
- Whisk together 2 1/2 cups flour, cocoa powder, baking soda, salt, and baking powder in a large bowl until thoroughly mixed.
- Beat in white sugar, 2/3 cup butter, water, 1 teaspoon vanilla extract, and eggs to make a smooth batter.
- Place chocolate chips into a bowl and mix with 2 tablespoons flour until the chips are coated; fold chocolate chips into the batter.
- Divide batter between the prepared muffin cups, filling each cup about 2/3 full.
- Bake in the preheated oven until a toothpick inserted into the center of a cupcake comes out clean, about 20 minutes. Remove from oven and let cool completely.
- While cupcakes are cooling, beat 1 cup butter, Irish cream liqueur, 2 teaspoons vanilla extract, and green food coloring with an electric mixer in a large bowl until mixture is smooth, thick, and evenly colored.
- Reduce mixer speed to low and beat in confectioners' sugar, 1 cup at a time, until frosting is desired consistency. Beat in more confectioners' sugar to make a stiffer frosting.
- Spread frosting on cooled cupcakes.