APPLE SPONGE CAKE

We adapted this recipe from the Spanish website 'www.pequerecetas.com' which is great.
You need:
- 150 gr butter (room temperature)
- 125 gr sugar
- 200 gr self raising flour
- 3 eggs
- 1 tsp baking powder
- 2 tablespoons milk
- a pinch of salt
- 1 teaspoon vanilla essence
- 1 tbsp of lemon juice
- 750 gr apples
-  apricot jam

Preheat the oven at 180 degrees.
Beat 125 gr of butter with the sugar. Add the lemon juice, vanilla essence and salt. Then add the eggs (one at a time) and finally fold in the flour and baking powder. Last add the milk. Put it all on a springform tin previously greased with butter.
Peel the apples and cut them into quarters. Cut each quarter along its length four times but leaving the tops joined (see picture). Put the apple quarters on top of the cake. Melt the remaining 25 gr of butter and with a brush 'paint' the apples with the butter. Bake in the oven for 45 minutes.
As you take it out of the oven, dilute two tablespoons of apricot jam with a tablespoon of boiling water and paint the top of the cake for a nice shine.