Do you have a favorite cookie recipe that you'd like to make into a bar? The key in the transition is to match the amount of batter to the size of the pan. A standard 9-by-13-inch pan will hold 4 to 5 cups of dough. When selecting which cookie recipe, a drop cookie dough works best. Others, such as rolled, shaped or batter recipes, may also work well; it just isn't as easy. Spread the dough in the pan and bake at 350 degrees for 20 to 30 minutes. There aren't any precise times for baking, so keep a close eye on them and check for doneness with a toothpick or cake tester. It should come out with only a few crumbs attached.