Mix corn syrup and evaporated milk in a microwave-safe 2-quart (2 L) bowl. Stir until well blended. Microwave on HIGH (100%) for 3 minutes. Stir in chocolate chips until melted. Stir in powdered sugar, vanilla and nuts. Beat 1 to 2 minutes with a wooden spoon until thick and glossy. Spread in 8-inch (20 cm) square pan lined with plastic wrap. Chill 2 hours or until firm. Cut into squares.