Step 1
Preheat oven to 350 degrees F (175 degrees C).
Step 2
Line 24 muffin cups with paper liners.
Step 3
Whisk together 2 1/2 cups flour cocoa powder baking soda salt and baking powder in a large bowl until thoroughly mixed.
Step 4
Beat in white sugar 2/3 cup butter water 1 teaspoon vanilla extract and eggs to make a smooth batter.
Step 5
Place chocolate chips into a bowl and mix with 2 tablespoons flour until the chips are coated; fold chocolate chips into the batter.
Step 6
Divide batter between the prepared muffin cups filling each cup about 2/3 full.
Step 7
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.
Step 8
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.
Step 9
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.
Step 9
Spread frosting on cooled cupcakes.