A flat metal baking sheet used to bake cookies, rolls, breads and pizzas. It has at least 1 edge that's turned up about 1/2 inch for easy handling.
How to Buy
Purchase cookie sheets small enough so there is at least 1 inch of space all the way around when placed in the oven. This space is needed for adequate air circulation and even browning. Use medium weight shiny aluminum cookie sheets for good heat conduction. Insulated cookie sheets with an air space between 2 metal sheets are popular and prevent overbrowning. However, some cookies and breads will not be crisp. Dark nonstick pans are also available, usually with a shallow edge on all 4 sides.
If cookie sheets are thin, double them for most even baking. When using dark nonstick cookie sheets, follow the manufacturer's directions. The oven temperature often needs to be decreased by 25°F to prevent overbrowning.