What burns cookies on the bottom?

1. Overbaking: Leaving the cookies in the oven for too long can cause the bottoms to burn, even if the tops appear to be done. Baking time can vary depending on the recipe and oven temperature, so it's important to keep a close eye on the cookies and remove them from the oven as soon as they are done.

2. Using a dark baking sheet: Dark baking sheets absorb more heat than light-colored ones, which can cause the bottoms of the cookies to burn more quickly. If possible, use a light-colored baking sheet for baking cookies, or place a piece of parchment paper between the cookies and the baking sheet.

3. Too high oven temperature: Baking the cookies at too high of a temperature can also cause them to burn on the bottom. Check the recipe to ensure you're using the correct temperature, and adjust the temperature if necessary.

4. Uneven oven heat: If your oven does not distribute heat evenly, it may cause some cookies to burn on the bottom while others are still undercooked. Try rotating the baking sheet halfway through the cooking time to ensure the cookies bake evenly.

5. Overcrowded baking sheet: Placing too many cookies on the baking sheet can prevent them from cooking properly and may cause the bottoms to burn. Make sure there is enough space between the cookies to allow for proper air circulation.