Preheat the oven to 300 degrees F. Butter and flour an 8-inch square pan.
Pour the batter into a greased and floured 8-inch square pan and bake for 45 minutes. Check for doneness with the tried-and-true toothpick method: a toothpick inserted into the center of the pan should come out clean. When it's done, remove to a rack to cool. Resist the temptation to cut into it until it's mostly cool.
Recipe courtesy of Alton Brown