Lucky Irish Brownies | Cooking Professionally

Ingredients

• 4 (1-ounce) squares unsweetened chocolate
• 1 cup margarine, softened
• 2 cups white sugar
• 3 eggs
• 2 1/2 teaspoons plus 1 tablespoon vanilla extract, divided
• 1 cup all-purpose flour
• 1/2 cup plus 6 tablespoons butter, softened, divided
• 4 cups confectioners' sugar
• 2 tablespoons milk, plus more, to taste
• 1 1/2 teaspoons peppermint extract
• 6 drops green food coloring, optional
• 1 1/3 cups semisweet chocolate chips