- 1 1/2 cups all-purpose flour
- 1 cup rolled oats
- 1 cup melted butter
- 1/2 cup brown sugar
- 1/2 cup graham cracker crumbs
- 1/4 cup chocolate sauce, or to taste, divided
- 1/2 gallon vanilla ice cream, sliced
- Preheat oven to 375 degrees F (190 degrees C). Grease a baking sheet.
- Mix flour, oats, butter, brown sugar, and graham cracker crumbs together in a bowl; spread mixture onto the prepared baking sheet.
- Bake in the preheated oven until lightly browned, about 15 minutes. Sprinkle half the oat mixture into a 9×13-baking dish; gently pat into dish. Drizzle half the chocolate sauce over oat layer.
- Arrange vanilla ice cream slices over chocolate layer; sprinkle the remaining oat mixture over ice cream layer. Drizzle the remaining ice cream sauce over cake. Cover dish with aluminum foil and freeze until set, at least 5 hours.