Lightly grease an 8- or 9-inch square pan. Heat the oven to 350°F. Sift the dry ingredients into a medium bowl. Add the remaining ingredients and stir to just moisten the dry ingredients; don’t overmix. Pour the batter into the pan. Bake until the edges are light brown and a toothpick inserted in the center comes out clean, 20 to 30 minutes. Let cool for at least 5 minutes before crumbling.