A cookie that spreads too much during baking comes out too thin, and may turn tough or overly crispy instead of soft. While some types of cookies are meant to come out thin, others work better as thick cookies with minimal spreading. The preparation of the cookie dough, pan preparation and baking methods affect how much the cookie dough spreads in the oven. Follow the recipe exactly -- including the ingredients, measurements and baking instructions -- to help reduce the spreading.
Heat the oven to the temperature specified in the recipe. A lower oven temperature gives the cookies more time to spread before they set. Preheating the oven to a higher temperature sets the cookies early in the baking time.
Measure the cookie ingredients exactly, combining them according to the recipe. Even a slight variation in measurements can affect the dough and make it spread more while it bakes.
Use margarine instead of butter if the recipe allows. Butter melts at a lower temperature, making it more likely to cause the dough to spread compared to doughs made with shortening or margarine.
Refrigerate the cookie dough before baking. The cooler dough takes longer to spread in the oven, allowing the cookie to set before it spreads too much.
Use nonstick cookie sheets to reduce the spreading. The grease on the pan makes the cookies spread more, so the nonstick pans are better if you want thicker cookies.
Line the cookie sheet with parchment paper instead of greasing it if you don't have a nonstick cookie sheet.
Place the cookie dough onto cool baking sheets. A hot baking sheet causes the dough to begin melting and spreading immediately.