Heat oven to 350°F. Spray 12-inch pizza pan with cooking spray. Break up cookie dough onto pan. Press dough in bottom and up side of pan to form crust. Bake 10 to 14 minutes or until light golden brown. Cool completely, about 30 minutes.
Stir hot fudge topping to soften. Spoon and spread about half of topping over cookie crust. Cover with scoops of ice cream, leaving 1/2 inch around edge.
Drizzle remaining topping over ice cream, heating topping if necessary. Sprinkle with peanuts. Freeze 30 minutes. Cut into wedges to serve.