INGREDIENTS: 3 eggs 85g caster sugar, plus 1 tablespoon extra 85g plain cake flour, sifted 1 teaspoon vanilla essence or extract For the filling: 1 tablespoon caster sugar flesh from two large, ripe granadillas 2 mangoes, peeled and diced 250g pack of fresh berries 200g tub of plain low-fat yoghurt (you can substitute full-cream yoghurt, or whipped cream, depending on your health needs)
Heat the oven to 200°C. Grease and line a 30cm x 24cm Swiss roll tin with non-stick paper. Place the eggs and sugar in a large bowl and beat with electric beaters until thick and light, about five minutes.
Fold in the flour and baking powder, then the vanilla.
Tip into the tin, tilt it to level the mix, then bake for 12-15 minutes until golden and just springy.
Turn on to another sheet of baking paper, dusted with one tablespoon of caster sugar.
Roll the paper up inside the sponge, then leave to cool completely (it even can be frozen, for up to one month).
Fold the sugar, granadilla pulp and one-third of the mango and berries into the yoghurt, along with the sugar.
Unroll the sponge carefully, spread it with filling, then roll up carefully again, with the open edge underneath.
Chill for up to two hours or until needed.
Serve with the rest of the fruit on the side.