Prepare Brownies: Preheat over to 350 F (180°C). Spray an 8 inch ( 20 cm) square pan with cooking spray. In a large saucepan, bring corn syrup and butter to a boil, stirring occasionally; remove from heat. Add semi sweet chocolate; stir until melted. Add sugar. Stir in eggs, one at a time, then vanilla, flour and nuts. Pour into pan. Bake 30 to 35 minutes, or until toothpick inserted in centre comes out clean. Cool completely on rack.
Prepare Glaze: In a small saucepan, melt 3 squares semi sweet chocolate with butter over low heat, stirring often. Remove from heat. Stir in 2 tbsp (30 mL) corn syrup and 1 tsp (5 mL) milk. Spread on top of brownies. Drizzle with white chocolate. Let stand until set. Cut into squares.