Mayflower Grape Cake 

1/2 cup shortening
1 1/2 cups sugar
3 cups flour
1/2 cup milk
1/2 cup water
1 1/2 tsp. vanilla
4 egg whites
Grape filling
Grape frosting

Cream shortening, gradually adding sugar, beating well. Combine dry ingredients, set aside. Combine milk and water. Add flour mixture to creamed mixture alternately with milk mixture, mixing well after each. Stir in vanilla. Beat egg whites until stiff peaks form, fold into batter. Pour into 2 greased,floured 9 inch cake pans. Bake at 350 F. For 25 minutes or until cake tests done. Let cool. Split each layer horizontally. Spread grape filling between layers, reserving 1/2 cup filling. Spread frosting on top and sides of cake and drizzle top of cake with reserved grape filling. 

Grape Filling

1 cup sugar
1/2 tsp. salt
1/4 cup plus 2 tbsp. cornstarch
1 cup grape juice
1 cup water
1/2 cup lemon juice
2 tbsp. butter or margarine

Combine sugar, cornstarch, salt, grape juice and water in medium saucepan, stirring well. Bring to boil and boil 1 minute, stirring constantly. Remove from heat; add lemon juice and butter, stirring until well blended. Cool.
 

Grape Frosting

1 1/2 cups sugar
2 egg whites
1/4 cup plus 2 tbsp. grape juice
1 tsp. corn syrup

Combine sugar, egg whites (at room temperature) grape juice and syrup in top of double boiler. Beat until well blended. Place over boiling water, beating constantly on high speed about 7 minutes, or until stiff peaks form. Remove from heat and beat until frosting is thick enough to spread.