There are a few different things that you can use to coat the ice cream and give it a crunchy exterior. For this version, I used basic graham cracker crumbs. You can also use things like crushed cookies, crushed cereal, or even plain bread crumbs with a bit of cinnamon and sugar mixed into them. Other ideas include a sweetened tempura batter, a tortilla dipped into butter and cinnamon sugar, or even just a cornstarch slurry with powdered sugar for sweetness.