How to prepare a great creamed mixture for cakes and sponge puddings:
1. Place the butter and 175g caster sugar in a mixing bowl and beat with a hand-held electric whisk until the mixture is almost white and has a soft dropping consistency. It should drop off the spoon easily when tapped against the side of the bowl. Patience is needed because the whisking will take at least 5 minutes and can be as much as 7 or 8 minutes. Keep checking the consistency. If you don't have an electric whisk use a wooden spoon. However you will be whisking away for about 20 minutes to reach the correct stage.
2. Add about one-third of the egg and beat well until thoroughly incorporated. Repeat this twice more until all the egg has been added and the mixture is the consistency of whipped cream.
3. Sift half the flour into the bowl then use a large metal spoon to fold it in carefully.
4. Sift in the remaining flour and fold in to give an evenly mixed soft consistency. The mixture is now ready to cook.
5. Butter the base and sides of two 20 x 4cm/8 x 11/2in) loose-bottom sandwich pans then line the bases with circles of greaseproof paper and butter these. Use the sugar and flour mixture to coat the sides of the tins shaking out the excess when evenly covered.
6. Preheat the oven to 190C/375F/gas mark 5.
7. Divide the mixture evenly between the tins. Level the surface then make a slight dip in the centre of each.
8. Cook just above the centre of the oven for 20-25 minutes until risen and golden brown and just firm yet spongy to the touch
5. Leave to cool in the tins until cool enough to handle, then turn out on to cooling racks and leave until completely cold. They may be stored in an airtight container at this stage for up to 1 week or frozen for 3 months.
6. Spread jam on the base of one cake then top with whipped cream and set the second cake on top.
7. Sprinkle with the sugar and serve at once.