Easy Fresh Blueberry Cake 1 (18.25 ounce) box yellow cake mix 2/3 cup water 1 egg 1/4 cup butter (NO SUBSTITUTE), melted 1 teaspoon ground cinnamon 1/8 teaspoon ground nutmeg 1 1/2 cups fresh blueberries Preheat oven to 350 degrees F. Grease a 9-inch square baking pan. Measure 2 cups cake mix into a bowl. Prepare remaining mix according to package directions, using 2/3 cup water and 1 egg. Measure 1 cup batter; set aside. Pour remaining batter into prepared pan. Add margarine, cinnamon and nutmeg to reserved cake mix. Mix until crumbly. Sprinkle half of the crumb mixture evenly over the batter in pan. Arrange blueberries evenly over crumb mixture. Spoon reserved batter evenly over top of blueberries. Sprinkle with remaining half of crumb mixture. Bake 45 to 50 minutes or until done. Serve warm.