Preheat the oven to 180c/fan 160c/350f/ gas mark 4
Line a 18cm/7inch deep cake tin and a shallow sponge tin of the same size for the spare cake.
The first five ingredients are for the sponge base. In a food processor or stand mixer (you could do it by hand too), beat the butter and sugar together until light and fluffy.
Beat in the eggs and vanilla extract, then fold in the self-raising flour.4, Divide the mixture in half. Put half in your deep cake tin for the cheesecake and the rest in the shallow tin for the spare sponge. Pop you spare sponge in the oven first, while you tackle the cheesecake.
Bake for 20 minutes until well risen, golden and firm to the touch.
Beat together the cream cheese, sugar, plain flour, soured cream, eggs and vanilla extract until well combined and smooth.
Fold in the raspberries, then pour the batter over your sponge base (deep tin). Smooth the top and cover with a good dusting of icing sugar.
Pop in the oven once your single sponge is out and bake for 1 hour and 30 minutes. Try the skewer test. There may be a bit of creamy cheesecake on the skewer, but it shouldn't be wet.
Turn the oven off and leave the cake to cool in the oven with the door open slightly.
Once cool, remove from the tin and decorate with whipped cream and raspberries.