Bake brownies by following package instructions or homemade recipe in a greased 9 x 13-inch pan at 350°F for 20-25 minutes.

Once cooled, cut two 6-inch circles from the brownies using a sharp knife or cake ring.

Assemble layers by placing one brownie circle at the bottom of a 6-inch springform pan, spreading one pint of softened ice cream over it, then topping with the second brownie circle and the second pint of ice cream.

Cover with plastic wrap and freeze for at least 4 hours until firm.

To serve, let the cake sit at room temperature for 5-10 minutes, drizzle with warm hot fudge sauce, and add optional toppings.