We may receive a commission on purchases made from links. We're going to let you in on a secret: Even the most accomplished home bakers probably have a box of cake mix tucked away in their pantry.

I'm a professional baker, but I swear by a boxed mix when it comes to making brownies. Ghirardelli triple-chocolate mix makes brownies with flaky tops and gooey middles. I let them cool fully and cut ...