Baking has a way of keeping you humble. • Just when you get all puffed up about your delicious successes, something falls flat. And I mean that literally. • It's the kitchen gods' way of keeping your ego in check. • The great equalizer in baking recipes in general is equipment. And during our testing sessions, we found that pans for bar cookies raised the most questions for us. Recipes called for jelly roll pans and half-sheets. Well, what size is that?
Some specified simply "baking pan." We were left to our own devices to figure that out. The Holiday Walnut Berry Bites on Page 5E, for example, were made twice because we suspected they would be better baked in a larger pan so that the base was thinner and thus firmer. The base of the first go-around was mushy.
We were right, and had good results using a 12 ½- by 17 ½- by 1-inch baking pan. Is that a half-sheet pan? Well, pretty close. A half-sheet is 18- by 13- inches. Are they interchangeable? Probably.
An all-purpose jelly roll pan is 15 ½ by 10 ½ inches, a different animal altogether. Both are good pans to have in your collection. Don't make the mistake of assuming just because a baking pan has a 1-inch lip, that it's a jelly roll pan. Let's just called it jelly-roll-like.
For bar cookies, it is best to use a pan that is within an inch of what's called for in the recipe, except in the case of the 9-inch and 8-inch squares. The 9-inch square pan holds 2 cups more than the smaller pan. If you are pressing a cookie base into an 8-inch square that's meant for the larger pan, you'll need to bake it longer because the base will be deeper. If you are doing the opposite, you'll need to bake it less.
Didn't know math was involved, did you? That's why baking is called a science. Those drop cookies are looking better and better.
I am a big fan of the 9- by 13-inch pan, using it for everything from cakes to bar cookies to baked pasta dishes and other casseroles. This workhorse baker is also called a quarter sheet, but again, it should only be used in baking when it's specifically called for.
I recommend selecting recipes that provide a specific pan size, especially if you are new to baking. I have found it's easy to lose the guessing game. For drop cookies, you can use many sizes and the main difference there is how many cookies you can fit on a sheet. Most cookie dough is placed 2 inches apart. I like larger sheets so I can bake at least 16 at a time, sometimes more depending on the size.
Baking diva Flo Braker, author of Baking for All Occasions (Chronicle Books, 2008), suggests having two of each pan or baking sheet you use, no matter the size. I like this idea, too, because it allows you to bake another batch when one is cooling. It's best to cool sheets between batches. If you plop cold dough on a warm (or hot) baking sheet it will spread quickly, resulting in wider, flatter cookies. Do your cookies often end up lacy and thin? This may be why.
other tips about baking sheets:
• Use heavy-gauge aluminum cookie sheets with a reflective surface. Dark, non-stick sheets make cookies darker (and ultimately crisper) on the bottom. You'll want to shorten bake times with these or use the lower time specified in the recipe.
• It's easier to remove cookies from rimless baking sheets.
• If you are using flexible silicone pans or sheets, use a rimmed baking sheet underneath to support them.
• Use parchment paper to line baking sheets rather than greasing. This helps facilitate even baking and makes cleanup easier. You'll get longer life out of your pans, too. Use parchment, too, for recipes that call for ungreased pans.
• Insulated cookie sheets help prevent burning, but because they have two layers of aluminum they can lengthen baking times. Also, you won't get crispy edges if you use these.
• Let cookies cool on hot sheets for about 2 minutes to firm slightly then remove gently to wire racks to cool completely. If you let them cool on the hot pan, they will continue to cook and possibly dry out.