After making these chewy brownies over and over, I have learned a few things when it comes to cutting them. First of all, it's best to let them cool down before you ever cut them. Secondly, using a plastic knife to slice the gooey brownies is a game changer. The plastic knife allows it to make clean slices, and fewer brownie crumbs will stick to the knife. Be sure to wipe off the knife after each pass if there are crumbs.