Cream the butter and sugar thoroughly until pale, light and fluffy. Beat the eggs, and gradually beat, a little at a time, into the creamed mixture. Once the eggs have ben incorporated, gently fold in the flour.
Spoon the batter into 2 × 20cm (8 inch) greased and floured sandwich tins, smooth the top, and bake in a preheated oven at 180°C/350°F/gas mark 4 for 20-25 minutes.
Allow to cool in the tin for a few minutes, and then ease the sponges out onto wire racks to cool.
To serve, sandwich with raspberry jam and whipped cream or with lemon curd. Sift icing sugar over the top before serving.
To make a chocolate cake, substitute 25-40 g (1–2 oz) flour for 25–40 g (1–2 oz) cocoa, and use a filling of melted chocolate folded into whipped cream. For a coffe cake, add to the original mixture two tablespoons espresso coffe, and use more coffe to flavour butter cream, a mixture of softened unsalted butter and icing sugar. Chopped walnuts can be added to the coffe cake batter for yet another version.