Holiday Coconut Cake

Originally printed in The Lexington School's 1981 Let's Entertain cookbook
Recipe submitted by Sugar Slabaugh, mother of Tommy Slabaugh '89 and Susie Slabaugh '92, grandparent of Sammy '19
Cake:
1/3 cup shortening
1/3 cup butter, softened
1 3/4 cups sugar
3 cups cake flour
3 1/2 tsp. baking soda
3/4 tsp. salt
1 1/3 cups milk
2 tsp. vanilla
4 egg whites, beaten
Cream shortening, butter, and sugar until light and fluffy. Sift dry ingredients together-add to creamed mixture, alternately with milk, beating well after each addition. Add vanilla. Fold in stiffly beaten egg whites. Pour batter into 3 greased and floured 8" cake pans. Bake 30 minutes at 350. Cool. Spread Lemon Filling between layers; frost top and sides with Fluffy Frosting; cover with freshly-grated coconut.
Lemon Filling:
1 cup plus 2 TBSP sugar
1/4 cup corn starch
1 cup plus 2 TBSP water
2 egg yolks
2 TBSP butter
3 TBSP lemon juice
1 TBSP lemon rind
Blend sugar and starch; gradually stir in water. Bring to a boil over medium heat, stirring constantly. Boil 1 minute. Stir in a small amount of hot mixture into slightly-beaten egg yolks; add eggs to hot mixture in saucepan. Boil 1 minute longer, stirring constantly. Remove from heat and stir until smooth. Add butter, lemon juice, and rind. Cool.
Fluffy Frosting:
1 cup sugar
1/3 cup water
1/4 tsp. cream of tartar
2 eggs whites
1/2 tsp. vanilla
1/2 tsp. almond extract
Freshly grated coconut
Combine 3 ingredients in heavy pan. Cook over low heat without stirring, until syrup spins a 6-8 in. thread. Beat egg whites until soft peaks form. Continue to beat egg whites, and slowly stir in syrup mixture. Add flavorings, beat well. Sprinkle frosted cake with coconut.