Method
Prep:30min  ›  Cook:12min  ›  Ready in:42min 

1. Preheat the oven to 200ºC (400ºF, gas mark 6). Grease a 33 × 23 cm (13 × 9 in) Swiss roll tin and line with baking parchment.
2. Put the eggs and sugar in a large bowl and beat with an electric mixer until the mixture is very thick and pale, and leaves a trail on the surface when the beaters are lifted out. (If using a hand whisk or rotary beater, set the bowl over a pan of almost boiling water, making sure the water is not touching the base of the bowl.)
3. Sift half the flour over the whisked mixture and gently fold it in with a large metal spoon. Sift over the remaining flour and fold in together with the tepid water.
4. Pour the mixture into the prepared tin and give it a gentle shake so that the mixture spreads evenly into the corners. Bake for 10–12 minutes or until the sponge is well risen and pale golden, and springs back when pressed gently with your finger.
5. Turn out onto a sheet of baking parchment slightly larger than the sponge. Peel off the lining paper. Trim the crusty edges of the sponge with a sharp knife and make a score mark 2.5 cm (1 in) from one of the shorter edges (this will make the sponge easier to roll up).
6. Roll up loosely from the short side, with the paper inside, and place seam side down on a wire rack to cool.
7. When the sponge is cold, carefully unroll it and remove the paper. Whip the cream with the vanilla extract until it forms soft peaks, then fol1/2 in the yogurt. Spread this mixture over the sponge, leaving a 1 cm (1/2 in) border all round. Scatter the fruit over the cream. Carefully roll up the sponge and place seam side down on a serving plate.
8. Lay 2 cm strips of kitchen paper or greaseproof paper diagonally, at an equal distance apart, over the roulade, then dust with the icing sugar. Carefully remove the paper, to leave a striped effect. Decorate with the extra fruit. Keep the roll in the fridge until ready to serve. This classic fatless sponge does not keep well and is best eaten within a day of making.

Each serving provides

A, B12, C * B2

Plus points

Strawberries are an excellent source of vitamin C – weight for weight they contain more than oranges. They also provide useful amounts of fibre and folate. * Peaches are another rich source of vitamin C and of vitamin A (from beta-carotene).

Some more ideas

For a simple jam Swiss roll, follow the main recipe to the end of step 5, then spread the sponge with 5 tbsp warmed jam and roll up. Sprinkle with 2 tsp caster sugar. Serve with fromage frais, if liked. * For a chocolate and raspberry Swiss roll, replace 3 tbsp of the flour with 3 tbsp cocoa powder. Use 170 g (6 oz) fresh raspberries in the filling instead of strawberries and peaches. Decorate with icing sugar and cocoa powder. * For a coffee sponge cake, pour 1½ tbsp almost boiling water over 2 tsp ground coffee, leave to infuse for 4 minutes and then strain. Fold the liquid into the sponge mixture instead of the tepid water. Divide the mixture equally between 2 greased and bottom-lined 18 cm (7 in) sandwich tins, then bake at 190ºC (375ºF, gas mark 5) for 20–25 minutes. Turn out and cool on a wire rack. Sandwich together with 5 tbsp warmed apricot jam. * For an orange sponge cake, whisk the finely grated zest of 1 orange with the sugar and eggs. Bake in sandwich tins as above.