What causes cookies to bake unevenly?

Several factors can contribute to cookies baking unevenly. Here are some common causes:

Uneven Oven Temperature: If your oven temperature is not consistent, it can cause cookies to bake unevenly. This can happen if the oven is not preheated properly or if there are hot spots or cold spots in the oven. Use an oven thermometer to ensure the temperature is accurate and adjust as needed.

Overcrowded Baking Sheet: Placing too many cookies on a single baking sheet can prevent them from baking evenly. Overcrowding can cause cookies to bake unevenly because they are too close together and the heat cannot circulate properly. Make sure to space cookies at least 2 inches apart on the baking sheet.

Different Cookie Sizes: If you have cookies of different sizes on the same baking sheet, they will not bake at the same rate. Larger cookies will take longer to bake, while smaller cookies may burn. Try to make all the cookies the same size to ensure they bake evenly.

Uneven Cookie Dough: If the cookie dough is not mixed properly, it can cause the cookies to bake unevenly. Make sure to mix the cookie dough until all the ingredients are well combined.

Old Baking Powder or Baking Soda: Old baking powder or baking soda can lose its potency, which can affect how the cookies rise and bake. Make sure to use fresh baking powder and baking soda.

Leavening Agent Problems: If you use too little leavening agent (baking powder or baking soda), the cookies may not rise properly and may bake unevenly. If you use too much leavening agent, the cookies may rise too quickly and collapse in the oven.

Oven Racks Not Centered: If the oven racks are not centered, the cookies may bake unevenly because they are not receiving heat evenly. Make sure the oven racks are centered before preheating the oven.