Heat oven to 350°F.
Beat egg whites and cream of tartar in large bowl until frothy. Beat in superfine sugar, 2 tablespoons at a time, until stiff, but glossy peaks form, 5 to 7 minutes.
Fold flour into egg whites in 2 additions, until incorporated. Fold chocolate chips into batter.
Spoon batter into 6 ungreased 4-inch tube pans.
Bake in 350°F oven for 22 to 25 minutes. Remove from oven and immediately invert onto baking sheet. Cool completely.
To serve, frost cakes with whipped topping. Garnish with raspberries and mint, if desired.