Yellow Citrus Cake

CAKE:
2 cups flour
2 1/2 teaspoons baking powder
3/4 teaspoon salt
2/3 cup shortening
1 1/2 cups sugar
1 tablespoon grated orange peel
1 1/2 teaspoons grated lemon peel
3 eggs
2/3 cup milk
2 tablespoons lemon juice

LEMON FILLING:
3/4 cup sugar
2 tablespoons cornstarch
1 dash salt
3/4 cup cold water
2 beaten egg yolks
1 teaspoon grated lemon peel
3 tablespoons lemon juice
1 tablespoon butter

Filling: In saucepan, combine sugar, cornstarch and salt. Stir in water. Add egg yolks, lemon peel, and lemon juice. Cook and stir till bubbly. Cook 1 minute more, then stir in butter. Cover surface with waxed paper and cool thoroughly before using.

Cake: Grease and lightly flour two 9-inch round cake pans. Combine flour, baking powder and salt. In a mixer bowl, beat shortening using medium speed for about 30 seconds. Add sugar and peels; beat until well combined. Add eggs, one at a time, beating 1 minute after each. Add dry ingredients, milk, and lemon juice alternately, beating after each addition. Turn into pans.

Bake at 350�F for 30 minutes or till done. Cool 10 minutes in pans. Remove from pans and cool on wire racks. Split layers horizontally. Spread Lemon Filling between layers.