Using a pizza stone to cook your mini pizza can be a great way to achieve a crispy crust, but it is not necessary. A pizza stone retains and evenly distributes heat, which can result in a more evenly cooked pizza. It also helps to absorb moisture from the crust, which can make it crispier. Just make sure your pizza stone is hot before you place your pizza on it. However, if you don't have a pizza stone, you can still achieve a delicious, crispy crust by baking your mini pizza on a preheated baking sheet, pizza pan, or a perforated pizza pan. These options will also help to evenly distribute heat and allow for air circulation, resulting in a crispier crust. Ultimately, whether or not you use a pizza stone when cooking a mini pizza is a matter of personal preference and convenience. If you have a pizza stone and enjoy the results it produces, then go ahead and use it. But if you don't have one or prefer a different method, that's perfectly fine too.