Lemon Platinum Cake

Directions

1. 1
   Heat oven to 325.
2. 2
   For Cake:.
3. 3
   In a large bowl, beat egg whites until foamy.
4. 4
   Add cream of tartar and 1/2 teaspoon salt and beat until soft peaks form.
5. 5
   Gradually add 1/2 cup sugar, beating until stiff peaks form. Set aside.
6. 6
   In small bowl, beat 7 egg yolks until lemon coloured, about 2 minutes.
7. 7
   Gradually add remaining 1/2 cup sugar, beating until thick and light lemon colored.
8. 8
   Add flour, 1/3 cup lemon juice and 2 teaspoons lemon peel to egg yolk mixture, beat at low speed for 1 minute.
9. 9
   By hand, gently gold egg yolk mixture into egg white mixture.
10. 10
    Pour batter into ungreased 10 inch tube pan.
11. 11
    Bake at 325 for 40 to 55 minutes or until top slightly springs back when touched lightly in center.
12. 12
    Let cool and remove from pan.
13. 13
    For Filling:.
14. 14
    In a small saucepan, combine 1 cup sugar, cornstarch and dash of salt. Mix well.
15. 15
    Gradually stir in water, cook over medium heat until mixture thickens and boils, stirring constantly; remove from heat.
16. 16
    In a small bowl, beat 2 egg yolks and gradually blend small amout of hot mixture into egg yolks.
17. 17
    Return egg yolk mixture to saucepan; cook over low heat 2 or 3 minutes or until thickened, stirring constantly.
18. 18
    Remove from heat; stir in 3 tablespoons lemon juice, butter and 2 teaspoons lemon peel. Cool.
19. 19
    For Frosting:.
20. 20
    Combine sugar, cream of tartar, salt, egg whites and lemon juice in a double broiler or mixing bowl.
21. 21
    Set over simmering water at medium heat, making sure not to tough bottom of bowl to the simmering water.
22. 22
    Beat with hand mixer at high speed for 7 minutes, or until stiff peaks begin to form.
23. 23
    Remove from heat and continue to beat at high speed until mixture is cooled and stands at soft, billowy peaks.
24. 24
    To assemble the cake, slice it horizontally to make 3 layers.
25. 25
    Place bottom layer on serving plate, spread with half of filling mixture.
26. 26
    Place middle layer on top, spread with remaining filling.
27. 27
    Top with third layer and spread sides, center and top of cake with frosting.
28. 28
    Refrigerate at least one hour before serving.