Put in the oven and bake for 15 to a max. 20 minutes (the less the fudgier). When a toothpick is inserted in the center, it shouldn’t come out clean. You want the brownies to stay sticky in the middle, but the outside should already be kind of crunchy. Don’t over-bake.
BTW, I’ve come across an excellent tip suggesting to bake brownies on the top rack. This way they are less likely to get dry while baking.