Biscuit de Savoie Recipe:
- Butter and lightly flour a 25 cm (10 inch) round springform tin.
- Line the base with a round of greaseproof paper.
- Sift the potato flour and the plain flour together twice.
- Whisk the egg yolks with three-quarters of the castor sugar and lemon rind in a large mixing bowl until they are very thick.
- Whisk the egg whites until stiff, but not too dry, then gradually whisk in the remaining castor sugar, whisking until very shiny.
- Carefully fold the sifted flours into the egg yolk mixture, then gradually fold in the egg whites.
- Pour the sponge mixture into the prepared tin and bake at 180ºC (350ºF) mark 4 for 40-45 minutes until very well risen, and a wooden cocktail stick or skewer inserted in the centre of the sponge comes out clean.
- Allow the sponge to cool in the tin for 10 Minutes, then transfer to a wire rack to cool completely.
List of ingredients required:
- 50 g (2 oz) potato flour.
- 50 g (2 oz) plain flour.
- 5 eggs, separated.
- 175 g (6 oz) castor sugar.
- Finely grated rind of 1 lemon