Chocolate Sponge Cake

Directions

1. 1
   Let eggs stand at room temperature for 30 minutes. In a large bowl, beat egg yolks until slightly thickened and lemon-colored, about 5 minutes. Stir in orange juice and vanilla until combined. Gradually beat in 1 cup sugar on low speed, about 2 tablespoons at a time, beating well after each addition. Beat on high until mixture thickens and nearly doubles in volume. Combine the flour and cocoa. Fold a fourth of the flour mixture into the yolk mixture. Repeat with remaining flour mixture; set aside.
2. 2
   In a large bowl and with clean beaters, beat egg whites and cream of tartar in medium speed until soft peaks form. Gradually beat in remaining sugar, about 1 tablespoon at a time, on high until stiff glossy peaks form and sugar is dissolved. Fold a fourth of the egg whites into the yolk mixture; fold in remaining whites.
3. 3
   Pour into an ungreased 10-in. tube pan. Bake at 325° for 55-60 minutes or until top springs back when lightly touched. Immediately invert pan; cool completely. Run a knife around sides and center tube of pan; remove cake.