Chocolate Sponge Cake

This week, my family from California visited me. As requested from my niece, I made this chocolate sponge cake for her. She really enjoyed it. Now, I want to share this recipe. From this cake recipe, I can prepare a breakfast parfait for her, and the rest can be served as dessert with vanilla ice cream.

Ingredients:
1 cup cake flour
1/4 cup cocoa powder
1/4 tsp salt
1/4 tsp cream of tartar
1/3 cup granulated sugar for egg white
1/4 cup granulated sugar for egg yolk
7 eggs (with egg yolks separated from egg whites)
1/4 cup skim milk

Directions:
In a bowl, combine cake flour, cocoa powder, and salt. Sift 3 times.
Let eggs assume room temperature before using.
Using the larger bowl of an electric stand mixer at medium speed, beat egg whites until foamy. Gradually beat in 1/3 cup granulated sugar, beating after each addition. Continue beating until stiff peaks form when beater is slowly raised.
Using the small bowl of the same electric stand mixer, use the same beaters at high speed, beat egg yolks until very thick with a pale yellow appearance (about 5 minutes). Gradually beat in 1/4 cup sugar; continue beating until smooth. Do not under beat. At low speed, blend flour and milk alternately into egg yolks mixture. Use a spatula to scrape the batter off the sides of the bowl.
With a whisk or rubber spatula using an under and over motion, gently fold yolk mixture into beaten whites mixture in larger bowl.
Pour batter into an ungreased 9” x 4.5” round pan without a removable bottom. Bake in a preheated oven set to 350° for 40 minutes or until cake springs back when pressed with finger. Invert and let cool completely.