A bit of bad news, I'm afraid. You really need to let these brownies cool completely before you cut them or they will cut messily and not hold their shape very well. It's best to leave the house to avoid temptation. But, hey, they're for a bake sale. You weren't going to actually eat one? Oh, okay, that'll cost you $1.00. By the way, the brownies are so much better, both in terms of taste and consistency, when they are completely cool-in fact they're even better the next day, firm and amazingly moist inside, with that gorgeous lightly crackled top crust. I have heard that these brownies can be stored in a tightly sealed container for up to five days, but this may be just a rumor.