HEAT oven to 350°F. Spray a 12-inch round pizza pan with no-stick cooking spray. Prepare brownie mix in large bowl as directed on package, including syrup packet, oil, water and egg. Spread onto prepared pan. Bake 16 to 20 minutes. Cool completely.
SPREAD can of chocolate frosting over brownie. Top with chocolate-covered wafer candies and chopped chocolate-covered peanut butter cups.
HEAT fudge and caramel toppings according to label directions; drizzle some of each over top of the pizza. Cut in wedges and serve.