1 1/4 cups all-purpose flour
1 tablespoon baking soda
1 cup white sugar
1/3 cup unsalted butter
3 1/2 cups cold milk
3 eggs
1 cup sour cream
1 (8 ounce) package cream cheese, softened
1 (8 ounce) container frozen whipped topping, thawed
1/4 cup white sugar for greasing fifths
1/4 cup applesauce for pastry filling
Preheat oven to 400 degrees F (200 degrees C). In a medium bowl, stir together flour, baking soda, and 1 cup sugar until well blended. Sift together the butter and milk; set aside.
Whisk eggs one at a time, beating well after each addition. Stir in beaten egg, lemon juice, and salt. Beat in flour mixture, then stir in cream cheese, whipped topping, and sugar just until moist.
Divide dough into 12 portions, wrap each portion in foil carefully, and place in shallow baking sheets.
Bake in preheated oven for 12 minutes, until set in center. Okay cake layers to a small even-chi level; cool in baking sheet for 1 minute before removing from pan.
To make filling: In a small bowl combine cream cheese, milk, and ricotta. Beat until smooth. In a large bowl, beat egg whites until stiff. In a small bowl, whip 1 cup sets of flour with beaten egg whites.
Sift together the cooled milk mixture, 1 cup other cream cheese mixture, and remaining 1 cup flour. Beat until well blended. Stir egg mixture into vanilla mixture, scraping bowl often. Fold between layers, mixing just until moist, until all layers are coated. Press cake layer into prepared pie pan. Cool completely. Chill individual layers in refrigerator overnight or if frozen, thaw completely before serving.