Yield: 4 (4-inch) cakes
1 cup sugar, divided
¾ cup cake flour
1 cup egg whites (about 6 to 7 large egg whites), at room temperature (see note)
¼ teaspoon plus 1/8 teaspoon cream of tartar
¼ teaspoon salt
½ teaspoon coconut extract
½ teaspoon vanilla extract
Garnish: confectioners’ sugar
1. Preheat oven to 350°. Sift together 1/2 cup sugar and flour. (This will help flour combine more evenly with egg whites.) Set aside.
2. To help egg whites achieve better volume, gently warm them in the top half of a doubler boiler, over simmering water, until they are slightly warm to the touch. Transfer egg whites to the bowl of a stand mixer. With the whip attachment, beat egg whites until they form soft peaks, adding cream of tartar and salt about 30 seconds after you begin beating. Gradually add remaining 1/2 cup sugar and extracts. Continue to beat until egg whites form soft, moist peaks. Do not beat until stiff.
3. Transfer egg-white mixture to a medium mixing bowl. Fold in flour mixture until it is just combined. Do not overmix. Spread batter in 4 ungreased 4-inch mini tube pans.
4. Bake until center is firm to the touch, approximately 25 to 30 minutes.
5. Remove cakes from oven, and immediately invert pans onto narrow-neck bottles. Let cool completely (approximately 2 hours). Using an offset spatula, loosen cakes from pan, and remove from pan. Garnish with confectioners’ sugar, if desired.
Note: Eggs will be easier to separate while they are still cold. Let egg whites come to room temperature, and refrigerate or freeze egg yolks to use in another recipe.