Using the correct ingredients is key. For best results, follow the recipe closely and measure ingredients carefully.
Fats Fats play a major role in the spread of a cookie--whether a cookie keeps its shape or flattens in the oven. In general, more fat equals flat, crispy cookies while less fat equals puffier, cake-like cookies.
Cookies are made primarily with butter, margarine or shortening. Whipped spreads are not suitable for baking.
Shortening and margarine are stable, and will help cookies keep their original unbaked shapes. Butter melts at body temperature--a much lower temperature than other solid fats--resulting in a “melt-in-your-mouth” burst of flavor.
Cookies made with butter tend to spread out. Butter is essential in certain cookies, such as shortbreads; if they don't hold their shape, consider lowering the amount of butter, sugar, or baking soda in the recipe.
Flour Flour also affects how cookies behave. Most cookie recipes call for all-purpose or pastry flour. Both bread flour, with its high protein content, and cake flour, which is high in starch, produce cookies that tend to spread less. (The gluten in the bread flour and the absorbent starch in cake flour are responsible for the similar results.) Higher flour-to-liquid ratios are needed in shortbread and crumbly-textured cookies.
Baking Powder and Baking Soda Baking powder and baking soda are the two most common leaveners in cookies. Baking soda is simply bicarbonate of soda, while baking powder is a combination of bicarbonate of soda plus cream of tartar, an acidic ingredient. Baking soda neutralizes the acidity of the dough, allowing the cookies to brown in the oven. Since baking powder already contains its own acid, it will not reduce the acidity in the dough, and the resulting cookies will be puffier and lighter in color.
Sugars Like fats, sugars liquefy in the oven. The type and amount of sugar used play a big role in cookie performance. White sugar makes a crisper cookie than brown sugar or honey. Cookies made from brown sugar will absorb moisture after baking, helping to ensure that they stay chewy. Most chocolate chip cookie recipes contain both brown and white sugars. If you lower the amount of sugar called for in a cookie recipe, the final baked cookie will be puffier than its high-sugar counterpart.
Cookies are not as delicate as cakes, but proper mixing is still important. Some recipes require a creaming step in which the fat and sugars are beaten together until light-colored and fluffy. Other cookies require a sandy texture, so the fat is cut into the flour. Over-mixing can incorporate too much air into the dough, resulting in flat, overly spread-out cookies. Follow the recipe instructions. Once you combine the dry and wet ingredients, mix until just combined.
Unless otherwise specified, ingredients should be at room temperature before mixing. Cookie dough that is chilled before baking will hold its shape better. Rolled and cut-out cookies should be refrigerated before baking for sharper, clearer edges. Drop cookies, such as chocolate chip or oatmeal cookies, can be at room temperature before baking; the spoonfuls of dough will spread and flatten out to the desired result.
Equipment and Baking
Different baking sheets and ovens produce different results. Thin baking sheets might allow the bottoms to brown too fast. Special insulated baking sheets allow air movement and help cookies bake evenly, but they can be expensive. Semi-thick rimmed baking sheets--also called jellyroll pans--are available just about everywhere, and are a fine multipurpose baking choice. Rather than greasing each baking sheet, consider investing in a roll of parchment paper or a nonstick pan liner to make cookie removal and clean-up easy.
Follow the recipe's instructions for baking. Invest in an oven thermometer to be sure your oven temperature is calibrated correctly. Generally, cookies are baked in a moderate oven--350 degrees F (175 degrees C)--for 8 to 12 minutes, depending on the size of the cookie. For chewy cookies, allow them to cool on the pan for 3 to 5 minutes before transferring to a cooling rack. For crispier cookies, let cool for one minute on the baking sheet before transferring to a wire rack.