Baking sheet

Often called a cookie sheet, this is made in a variety of metals; the best are heavy and will not warp at high temperatures. The sheet should be at least 1 in/2.5 cm smaller than the oven on all four sides to allow air and heat to circulate. Heavy aluminum baking sheets, particularly those with a nonstick finish, are gaining in popularity. Sheets with little or no rim make baked goods easy to remove. A bar cookie pan is somewhat deeper, intended for cookies to be cut into squares.