Preheat the oven to 180°C, fan 160°C, gas 4. Grease 2 x 20cm cake tins with a little melted butter. Dust with a little flour and shake out the excess.
Put the eggs and caster sugar in a large bowl and whisk with an electric whisk or in a mixer for about 10 minutes until doubled in size, very pale, thick and moussey. Gently fold in half the flour, followed by the remaining flour. Carefully pour in the melted butter and fold in until just incorporated.
Pour the mixture into the tins and bake for 25 minutes or until springy to the touch. Leave to cool, then turn out and cool completely on a wire rack.
Beat the soft cheese and yogurt with the maple syrup and vanilla extract. Put 1 sponge on a serving plate and spread with half the filling. Decorate with half the mixed fresh summer berries, then lay the other sponge cake on top. Spread over the remaining cream. Decorate with the remaining fruit and dust with icing sugar to serve.