Heat oven to 350°F. Line 12-inch pizza pan with foil; grease foil with shortening. Cut cookie dough into 1/4-inch slices; arrange in pan. With floured fingers, press slices to form crust.
Bake 25 to 30 minutes or until deep golden brown. Cool completely, about 30 minutes.
Use foil to lift crust from pan. Carefully remove foil from crust; place crust on serving platter or tray. In small microwavable bowl, place marshmallow creme. Microwave uncovered on High 15 seconds to soften slightly; stir until smooth. Spread marshmallow creme over crust. Sprinkle candy-coated chocolate candies, pretzels and cut-up candy bars evenly over top.
Drizzle melted chocolate over cookie pizza. Cut into wedges or squares.