In a heavy saucepan, melt chocolate chips with 1 cup milk. Remove from the heat; stir in vanilla. Spread half into a waxed paper-lined 8-in. square pan; chill for 10 minutes or until firm. , Meanwhile, in a heavy saucepan over low heat, cook and stir candy coating with remaining milk until coating is melted and mixture is smooth. Stir in peppermint extract and food coloring. Spread over bottom layer; chill for 10 minutes or until firm. , Warm remaining chocolate mixture if necessary; spread over mint layer. Chill for 2 hours or until firm. Remove from pan; cut into 1-in. squares.