Here are some helpful solutions for the common causes:
Check package to make sure what you used contained at least 70% fat. A spread with less fat, diet "margarines" or spreads in tubs contain have too much water. The water creates steam, causing the cookies to puff.
Low protein flours, such as cake flour, absorb less water, leaving excess water to create steam, which causes the cookies to puff. Unless the recipe directs otherwise, use a national brand of all-purpose flour. Learn more about flour.
- Sea level recipe for cookies may give acceptable, but different results at high altitudes. It is best to bake a test cookie to determine if different amounts of flour and/or liquid, or temperature changes are required.
- Cookies may or may to need a 15 to 25°F temperature increase, depending on other ingredients used.
- Substitute brown sugar for granulated sugar.
- Be careful not to overmeasure dry ingredients or overbake the cookies. Learn more about High-Altitude Baking.