Philadelphia  - Sometime around the turn of this century, cookie recipes started adding a step to the baking process. There must have been a sizeable increase of complaints that cookies were browning unevenly because cookbooks began inserting the notation to rotate the cookie sheet (side to side and back to front) halfway through the eight- to ten-minute cooking time.

Given those directions, at the halfway mark you will be opening the oven door, allowing heat to escape, turning the baking sheet 180 degrees, and subjecting the cookies to a potential jolt and chilly draft while they are still in the process of expanding and haven’t yet fully stabilized. It’s certainly not something you would do to a soufflé.

Instead of this awkward manipulation, I would suggest instead acquiring heavy-duty aluminum baking sheets that can be found at any restaurant supply store for minimal cost. Choose the shiny ones, not the darker or nonstick variety that brown cookie bottoms much too fast. Get two or three—or more if you do marathon baking during December, also regarded as national cookie baking month. You’ll be glad you did. Home ovens normally can accommodate half sheets that measure 18 x 13 inches (but smaller quarter sheets also are available). A professional oven takes a full size.

These standard baking sheets have a low-rimmed edge, and it’s my feeling that those very sides help protect the outer cookies from browning too quickly. I also recommend baking in the upper half of the oven—contrary to many recipes. The heat reflected off the roof of the oven cooks the top of the dough, and the bottom of the cookies are kept far enough away from direct heat to prevent scorching. While I sometimes am flummoxed by other cookie issues, burnt bottoms have never been a problem. Nevertheless, I suggest baking a couple of test cookies before proceeding at full tilt. It never hurts to do that, and they will provide motivational nourishment.

Please bake one sheet at a time. By the time it’s out of the oven, you’ll have another sheet ready to go in and you’ll quickly establish a rhythmic pattern. (Use a small spring-handled scoop to portion so the cookies are all more or less the same size.)

One last thought. If you tend to get distracted, set the timer for a minute less than the recommended minimum. That way, when the dinger dings and your hands are sticky with cookie batter, you’ll have a minute to rinse and dry your fingers and find the pot holder before opening the oven door. Cookies are done when the tops feel “set” when lightly touched.

Thoughts on Writing
About the same time cookbooks began espousing rotating baking sheets, The Chicago Manual of Style amended its long-standing view on the serial comma. The 16th Edition now states, “When a conjunction joins the last two elements in a series of three or more, a comma—known as the serial or series comma or the Oxford comma—should appear before the conjunction. Chicago strongly recommends this widely practiced usage, blessed by Fowler and other authorities, since it prevents ambiguity. If the last element consists of a pair joined by and, the pair should still be preceded by a serial comma and the first and.” Examples can be seen in Chicago at reference 6.18, page 312, or above in the second paragraph.

While I see no need to encourage sheet rotation, I have long endorsed the serial or series comma (or the Oxford comma, for that matter) and wholeheartedly recommend it to anyone who doesn’t use it already.