Method
1. Grease and base line 2 20cm sandwich tins
2. Pre-heat oven to 180C/350F/Gas 4.
3. Beat margarine, sugar, eggs, flour and baking powder until thoroughly blended.
4. Divide the mixture between the 2 tins
5. Bake for 25mins or until well risen.
6. Turn out of tins and cool on a rack.
7. When cold, sandwich the cakes together with the jam and sprinkle the top with caster sugar.
