Preheat your oven to 350F/180C
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