This fancy cake is easy to prepare and always impress family and guests.

Set the oven rack in the center of the oven. Preheat the oven at 350 °F (180°C). Butter a spingform pan.
In a medium or large bowl, cream butter and sugar. Add eggs and beat until homogenous.
In another bowl, mix flour and baking powder and mix in batter until just blended not more.
Pour the batter in the pan; don't be surprised you will have a thin layer of dough.Insert apple slices, rounded sides upward, in the dough. Bake in the oven 30 to 40 minutes until a toothpick inserted in the center of the cake comes out clean. To add more time: 5 minutes .

Liquefy jam or jelly over low heat in a small saucepan or in the microwave. Glaze the cake with the jam with a pastry brush. Let cool 30 minutes before serving.
For a glamourous, put a couple of spoon of icing sugar in a sieve and shake the sieve over the cake just before serving. This step is done at the last minute otherwise the icing sugar will disappear in the glaze.