Time to make: 1 hr 30 mins, plus 1 hr cooling
1/2 cup castor sugar
3/4 cup plain flour
1 tablespoon boiling water
few drops vanilla essence
3 cups frozen mixed berries
4 tablespoons reduced-sugar black cherry or blackcurrant jam
2 teaspoons to 1 tablespoon cornflour
6 tablespoons berry flavoured reduced-fat yoghurt
Step 1 Preheat the oven to 190°C. Line the base of a 21cm diameter round cake tin with baking paper. Spray the tin with non-stick cooking spray.
Step 2 Place the eggs and sugar in a large bowl and mix with an electric mixer until the mixture has trebled in size and is thick and creamy (this will take about 6-10 minutes depending on the power of your mixer). The beaters should leave a thick trail on the surface when they are lifted.
Step 3 Sift half the flour over the mixture and fold in lightly, using a metal spoon. Sift in the remaining flour and fold in with 1 tablespoon water and the vanilla essence.
Step 4 Pour the mixture into the tin and tilt the tin to spread the mixture evenly. Bake for 25 minutes until lightly risen, golden brown, firm to touch and beginning to shrink from the sides of the tin. Cool the sponge for 5 minutes before removing from the tin.
Step 5 For the topping, heat the mixed fruits in a pot until the juices begin to run and the fruits are softened. Stir in the jam and heat through. Mix the cornflour with a little of the juice to make a paste. Stir into the fruits and heat for a few minutes to thicken. Serve over the sponge with some yoghurt if desired.