Simmer the apricots and apple juice in a saucepan, covered, for 10 minutes or until most of the liquid has been absorbed. Purée then leave to cool.
Make the sponge. Put the eggs, sugar and orange rind in a large heatproof bowl set over a saucepan of gently simmering water. Whisk, using an electric whisk, for 5–10 minutes until very thick and foamy and the whisk leaves a trail when lifted above the mixture.
Gently fold in the sifted flour. Pour the mixture into a 30 x 23 cm (12 x 9 inch) roasting or a swiss roll tin lined with nonstick baking paper (see
Meanwhile, cover a clean damp tea towel with nonstick baking paper and sprinkle with a little caster sugar. Quickly turn out the cooked sponge on to the sugared paper. Carefully peel off the lining paper. Spread the apricot purée over the sponge then, starting with a short side and using the paper to help, roll up to form a log. Leave to cool and serve the same day.