Cream sugar and butter. Blend in eggs, chocolate syrup, flour, and baking powder. Put in greased 15x10x1-inch jelly roll pan. Bake at 350°F for 20 minutes. Chill in refrigerator.
Filling
Cream butter and powdered sugar. Blend in milk, peppermint extract, and food coloring. Spread evenly over crust. Refrigerate until firm.
Frosting
Melt butter and chocolate chips over low heat, stirring constantly (you can microwave this). Pour over filling. Chill slightly, cut into squares. Return to refrigerator until hard.