Apple cake

1. * do not put the egg yolks together as they will be used individually.
2. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++ peel apples, cut in half and core.
3. Cut decorative lengthwise slits in apples, about ½-inch deep.
4. Sprinkle with lemon juice and sugar.
5. Set aside.
6. Cream butter and sugar together.
7. One at a time, beat in egg yolks.
8. Gradually beat in lemon juice and grated peel.
9. Sift baking powder and flour together.
10. Gradually add to batter.
11. Blend in milk and rum.
12. In a small bowl, beat egg whites until stiff.
13. Fold into batter.
14. Generously grease a springform pan.
15. Pour in batter and top with apple halves.
16. Brush apples with oil.
17. Bake in a preheated 350 °F.
18. Oven for 35 to 40 minutes.
19. Remove from pan and sprinkle with confectioners" sugar