While it is not necessary to chill this cookie dough, if you want to make ahead, you can keep this brownie cookie dough refrigerated. However, I recommend scooping the dough first and refrigerating the dough balls because the dough will harden and become difficult to scoop if you don’t portion it right away after mixing. Note that cold cookie dough won’t spread as much, so you could allow the dough to come back to room temperature before baking.