Ingredients
Method
1.Set a rack just below the middle of the oven and preheat oven to 160°C. Lightly butter 2 x 25cm sponge tins, then dust with sugar and then flour.
2.Beat the egg yolks, vanilla extract and sugar in an electric cake mixer on high speed until mixture is thick and leaves a trail off the uplifted beaters (about 7 minutes).
3.Sift together plain flour and potato flour with a large pinch of salt. Fold into whipped eggs and sugar with a large spoon, taking care not to knock out air.
4.Whip egg whites until stiff but not dry. Mix a large spoonful of egg white through the cake batter to lighten it, then carefully fold in the remainder without knocking out any air.
5.Immediately pile mixture into sponge tins (work quickly, don’t knock tins and don’t smooth over the top – if it is uneven, gently tilt the tin to level it).
6.Bake for 50 minutes, or until well risen, browned and firmish to the touch in the centre of the cakes. Turn off oven and let the cakes rest in the oven with the door ajar for 15 minutes.
7.Run a thin-bladed knife between sponge and tin to loosen. Turn cakes onto cooling racks lined with baking paper and cool.
8.Fill with whipped cream and chosen conserve, jam or curd. Dust top with icing sugar and freeze-dried raspberry powder, if using. Slice with a serrated knife to serve.
Freeze-dried raspberry powder is available from specialist food stores.
Note
