Grease 2 x 20cm (8inch) round sponge tins and line bases with baking paper. Preheat oven to 180C. Sift flours and 1/4 teaspoon salt together three times to aerate.
Using a stand or hand mixer, beat eggs and sugar on medium-high speed for about 6 minutes, or until mixture is thick, pale and tripled in volume. Gradually sift flour mixture over egg mixture while simultaneously folding in with a large metal spoon until just combined. Divide mixture between prepared tins - I like to weigh them so I know they'll be equal in size when cooked. To level batter, gently spin tins on kitchen counter.
Bake for 20 minutes or until cakes have shrunk away from the sides of the tins slightly, and spring back when gently touched. Turn out on to baking paper-lined wire racks. Carefully peel away base parchment paper, then leave to cool. Fill with whipped cream and your choice of preserves and/ or fresh fruit. Dust with icing sugar.