Peel, core and slice your apples. Arrange them on the bottom of a buttered and floured 9" spring form pan.
Whip eggs, sugar and vanilla until tripled in size for 10 minutes. Add sifted flour to the egg mixture in 4 additions, blending each addition gently. Pour the batter into the pan and smooth the top.
Bake in the preheated oven for 50-60 minutes or until a cake tester comes out clean. Let cool for 20-30 minutes and then remove the sides of a springform pan