A "double crust" refers to a type of pastry used in baking, particularly for pies. It consists of two layers of dough: one on the bottom that holds the filling and another on top that covers it. This design helps to seal in moisture and flavor while providing a crispy texture. Double crusts are commonly used for fruit pies, such as apple pie or cherry pie, where the filling is visible through slits in the top crust. The technique allows for various decorative options, enhancing the pie's appearance while ensuring a delicious, flaky result.