Yes, you can use aluminum foil to make a cake crust. It's a common practice to line the bottom of a cake pan with aluminum foil to prevent the cake from sticking and to make it easier to remove the cake once it's baked. However, it's important to ensure the foil is heavy-duty and doesn't tear during the baking process. Additionally, while foil can be used for many types of cakes, it's not suitable for all recipes, especially those that require a specific crust texture or those that bake directly on the foil without a pan.