Preparation / Directions:
1. To prepare for cake, grease two 8-inch cake pans, line with waxed paper, grease and flour bottom and sides, then shake to remove excess flour.
2. Beat egg yolks, 1/3 cup sugar, salt, lemon rind, juice and extract until thick and lemon-colored; stir in flour.
3. Beat egg whites in a separate bowl until soft peaks form; gently fold egg whites into flour mixture.
4. Pour mixture into prepared pans; bake in preheated 400 F. oven 15 minutes.
5. Remove from pans, remove waxed paper and cool.
6. To make filling:
a. In a saucepan, blend milk, soup, 1/2 cup sugar, cornstarch, rum and vanilla until smooth.
b. Cook over low heat, stirring until thickened.
c. Remove from heat; pour 1 cup hot liquid into beaten egg yolks, stirring constantly.
d. Stir egg mixture into soup mixture; cook over low heat, stirring until thickened.
e. Cover with waxed paper; cool to room temperature.
7. Cut each cake layer horizontally in half; spread 1/2 filling between each layer.
8. Stack layers; sprinkle top with confectioner's sugar and garnish with lemon slice