What to do: In a bowl, mix flour and confectioners sugar. Set aside. In a large, clean mixing bowl, beat egg whites, salt, and cream of tartar until foamy. Beat granulated sugar in, 2 tbsps. At a time, until stiff peaks form. Gently fold in vanilla. Next, sprinkling about 1/4 cup at a time, gently fold in flour/sugar mixture just until it disappears into your meringue. Push 3/4 batter into an ungreased bundt pan. Spoon 1/4-1/2 container of the whipped topping over batter, making a layer. Then spread the blueberries over that to make another layer. Top with a final layer of the remaining batter. Bake at 375 degrees for about 35-40 minutes. Serve with a dallop of whipped topping. (Very good warm out of the oven!)