Begin by preheating your oven to 350°F (175°C) and gathering your ingredients. In a large mixing bowl, sift together the cake flour and half of the sugar. In a separate bowl, beat room temperature egg whites until frothy. Gradually add the remaining sugar, cream of tartar, and salt until glossy peaks form.

Gently fold the flour mixture into the beaten egg whites. Pour the batter into an ungreased angel food cake pan and bake for approximately 30-35 minutes or until golden brown.

Remove the cake from the oven and invert it in the pan to cool for about 1 hour. Loosen the edges with a knife and remove it from the pan.

To make the seven-minute frosting, combine sugar and water in a saucepan over medium heat. Stir until clear. In a heatproof bowl, place egg whites and cream of tartar. Once the syrup reaches soft-ball stage, drizzle it into the egg whites while whisking until stiff peaks form.

Spread the frosting over the cooled cake and sprinkle with sweetened flake coconut. Slice and serve the Coconut Cloud Cake.