Get a perfectly lined baking pan, even if you failed geometry.
Lining a baking pan with parchment paper is one of the easiest ways to save time and energy when making brownies, cakes, or any other baked good. If you've used parchment, after your goods are baked and cooled, all you have to do is lift the edges of the paper to pull your treat out of the pan. From there, you can peel off the parchment and cut your baked good into portions—no awkward knife-maneuvering in the pan, no risk of damaging the pan.
Lining your baking pan with parchment is also helpful if you’re planning on freezing your treats. You can simply remove the entire batch from the pan and wrap it up in plastic wrap, then place it in the freezer. This way, you keep the baking pan available for more baking projects.
Plus, if you’re careful and don’t spill any batter on the pan before baking, there is no need to wash the pan when finished.
Are you sold? Here’s how to line an 8- by 8-inch baking pan with parchment paper so the paper sits smoothly and doesn't rumple into a big mess:
First, pull out the parchment and cut it to be approximately 14 inches long (this will give you 3 inches of overhang on each side of the pan). Next, fold 3 inches of one side of the parchment onto itself. Take the opposite side of the parchment and repeat the process.
Fold in each of the remaining sides the same way, 3 inches in, until you have a square-shaped piece of parchment. Place the folded parchment square into the 8 by 8 baking pan. If your square does not fit properly in the pan, simply adjust the folds as needed until it fits in place.
Now, lift the two top folds, on the left and right side of the pan, so that they are standing up facing each other. Next, lift one corner of the remaining side of parchment that is still lying down in the pan. Allow it to naturally fold onto itself, a triangular shape, as you raise it up to the side of the pan. Firmly press and crease the folded corner of parchment into place. Repeat the process with the remaining three corners. You are now ready to bake!
This technique will work for any four-sided baking pan you choose to use (whether 8 by 8, 9 by 9, 9 by 13, etc). Simply adjust the amount of overhang for the size you are using and trim down any excess parchment. For instance, if you’re using a 9- by 13-inch pan, first pull out the parchment and cut it to be approximately 4 inches longer than the 9 by 13 baking pan. You will want 2 inches of overhang on each side of the shorter edges of the pan. Repeat the exact same process as the 8 by 8 pan, only fold each side 2 inches in onto to itself instead.
Regardless of the size pan you’re using, the important part to remember is to make sure you have enough parchment overhang to cover up the entire inside of the baking pan.