From the cookbook "Here Are The Cakes America Loves", 1950:
Coconut Queen Party Cake with Marshmallow Frosting
Cake:
• 2¾ cups cake flour, sifted
• 4 teaspoons baking powder
• ½ teaspoon salt
• ¾ cup shortening
• 1½ cups sugar
• 4 egg whites
• 1½ teaspoons vanilla extract
• 1 cup milk
Sift together dry ingredients and set aside. Cream shortening thoroughly. Gradually add the sugar, mixing continuously. Add egg whites, one at a time, beating well after each addition. Add sifted dry ingredients alternately with the milk, beating until smooth after each addition.
Pour into 2 well-greased 9-inch cake pans. Bake at 350°F for about 35 minutes. Cool layers slightly and remove from pans. Cool completely.
Frosting:
• 2 egg whites
• 1½ cups sugar
• 6 tablespoons water
• 6 large marshmallows, quartered
• 1 teaspoon vanilla extract
• ¼ teaspoon baking powder
In the top of a double boiler, combine first 4 ingredients. Cook over rapidly boiling water, beating with a rotary egg beater about 10 minutes, or until mixture stands in peaks. Remove top of double boiler from heat.
Add the vanilla extract and baking powder and beat about 5 minutes, or until frosting is thick and of good spreading consistency.
Sprinkle 1 cup of grated coconut over top and sides. If desired, tint coconut by placing it with 2 drops of liquid food coloring in a covered pint jar. Shake until coconut is evenly tinted.
source: adapted from midcenturymenu.com.