You'll feel like a magician when you make this silky, rich ice cream using just a single ingredient—no milk, sugar, or even water necessary. Simply peel bananas and slice them into two-inch pieces (one banana per person is a good rule of thumb), then freeze for at least three hours. Using a food processor, puree the frozen bananas for five minutes, stopping occasionally to scrape down the sides of the bowl. The bananas will seem crumbly at first and then become fluffy and smooth. Serve the dessert plain—or for a fun take on a banana split, add toppings like chopped walnuts and chocolate chips.