The addition of ricotta cheese to a lemon sponge cake mixture is pure genius. The ricotta makes for a richer texture, making this cake perfect as it is - no need for filling or icing. Serve dusted with icing sugar, if desired.
For a little extra sweetness and lemon flavour, combine about 100g of icing sugar with a few teaspoons of lemon juice. Stir till smooth, adding more sugar or juice till a drizzling consistency is reached. Drizzle the lemon icing over the cooled cake just before serving.