What is the primary purpose of a baking sheet in pastry making?

The primary purpose of a baking sheet in pastry making is to provide a flat, stable surface on which to bake various types of pastries and baked goods. When considering the options, using a baking sheet as a bottom for a flan ring is relevant because the flan ring needs a solid base for baking, allowing even heat distribution and support during the cooking process. This helps in achieving the desired texture and doneness of the flan.

While it is true that a baking sheet can be used to bake cakes, it is not limited to large cakes only; it is versatile and can accommodate cookies, pastries, and other baked items as well. Additionally, although cooling down pies is an important part of the pastry process, it is typically done on a wire rack rather than directly on a baking sheet. Finally, using a baking sheet as a platter for desserts does not align with its primary function in the baking process. Instead, it serves practical purposes in the oven, such as ensuring proper baking and easy transfer of items in and out.