You've double-checked your oven temperature. You're using a reliable recipe. Yet your cookies are coming out too brown on the bottom, or perhaps pale and under-baked. What gives? The savvy folks at the King Arthur Flour blog may have found the problem — as well as a simple solution that ensures perfectly browned cookies every time.
The short answer: it's all about the pan you use.
PJ Hamel at King Arthur Flour's excellent baking blog decided to run some side-by-side cookie tests using aluminum sheet pans with various surfaces, including one with a very shiny finish, a standard half-sheet pan, a specialized King Arthur Flour baking sheet, and a much-loved sheet pan blackened by years of use. She baked on each pan both with and without parchment paper, and the results can be seen in the above-left photo.
The pans used, from top to bottom: old and blackened pan; King Arthur Flour pan; standard half-sheet pan; and shiny finish pan.
As you can see, the old, dark-finish pan turned out cookies that were far too brown, while the pan with a very shiny finish produced pale-bottomed cookies. Parchment paper helped, but the real solution, says Hamel, is taking the surface of your baking sheet into account when determining baking time. The above-right photo shows cookies baked on the same pans, with adjusted cooking times — a little shorter for the darker-colored pans and longer for the shiny pan — which produced evenly browned cookies. (Half-sheet pans, our favorite kitchen workhorses, needed no adjustments.)
Bottom line: if you're in the market for new cookie sheets, half-sheet pans are the way to go. But if you already have a stockpile of less-than-ideal cookie sheets, there's no need to replace them. Just remember to line them with parchment paper and adjust the baking time accordingly when making a batch of cookies.
→ Read more: The Secret to Perfectly Browned Cookies at Flourish, the King Arthur Flour blog
Do you have any tips for baking better cookies?