Mix crushed oreos with melted butter in a medium bowl. Press mixture into a 9x13-inch baking dish.
Freeze for 5 minutes until the crust is set. Evenly spread the softened ice cream over the oreo crust and place back into the freezer for another 20-30 minutes, until the ice cream is frozen solid.
Top with hot fudge sauce over ice cream. Evenly spread frozen whipped topping over hot fudge sauce and cover with foil. Freeze until frozen, at least 2 hours. Keep refrigerated until serving.