Sponge Fingers

Heat the oven to 180°C (160° fan) 350°F gas 4. Line 3 baking trays with non-stick baking paper.

Whisk together the egg yolks and half the sugar in a mixing bowl with an electric whisk until thick and creamy. Stir in the orange zest and vanilla.

Sift in the flour and gently stir until blended.

Whisk the egg whites to soft peaks, then gradually add the remaining sugar and continue whisking until stiff peaks form.

Gently fold into the mixture until just incorporated.

Spoon into a piping bag and pipe 8 -10cm|3"-4" lengths, spaced well apart, onto the baking trays.

Sift icing sugar over the piped biscuits and wait until absorbed, then sift over a little more.

Bake for 8-10 minutes, until lightly golden on the edges but spring back in the centre. Cool on the trays for a few minutes, then place on a wire rack to cool completely.

For the icing: sift the icing sugar into a bowl and beat in enough orange juice until the icing is thick enough to coat the back of a spoon. Add water if needed.

Carefully spread some of the icing on the sponge fingers.