Line 8-inch square pan with foil, leaving foil hanging over 2 sides for easy removal. Grease foil with butter.
In medium microwavable bowl, microwave white chocolate and butter uncovered on Medium-High (70%) 1 minute 30 seconds to 2 minutes, stirring every 30 seconds, until mixture can be stirred smooth. Stir in the 2 cups snack mix that has been crushed, until completely coated; press in pan. Set aside.
In 2-quart saucepan, heat condensed milk and vanilla baking chips over low heat, stirring frequently, until melted. Quickly stir in vanilla. Spread over snack mix layer in pan. Sprinkle with the 1/2 cup snack mix that has been crushed. Sprinkle with red sugar. Refrigerate about 2 hours or until set.
Remove fudge from pan. Cut into 8 by 8 rows. Store tightly covered up to 2 weeks with waxed paper between layers.