What are 9×13 desserts? Basically, they’re any type of dessert made in a 9×13 pan. That means treats like cakes, brownies, and cookie bars can fall into this category. Easy to transport, 9×13 dessert recipes are popular when you need to bring a dessert somewhere. The next time you’re heading to a potluck party or want to bring a treat to a friend, any of these desserts baked in a 9×13 pan will be perfect.