Preheat the oven to 350 degrees F. Place the dry ingredients into an 8 x 8-inch baking pan. With a fork or small whisk, mix until well combined. Add the remaining ingredients and mix until well combined. Bake 30 to 35 minutes, or until toothpick inserted in centre pulls out clean. Cool the cake on a baking rack, then, if desired, dust with icing sugar. Serve the pieces on their own or with whipped cream or vanilla ice cream.