A paste of just ground almonds, sugar and egg white, marzipan is the traditional base for cakes iced with royal icing (below). Ready-to-roll white marzipan is of excellent quality, and it can be lightly kneaded then rolled into shape. Brush the cake top with melted, sieved apricot jam to help the marzipan stick. Marzipan can also be an effective decoration on its own, with pinched edges, an egg-white glaze and a sprinkling of sugar.
For a 23cm (9in) round or 20cm (8in) square deep cake, brush the top and sides with about 4 tablespoons sieved melted apricot jam. Knead 500g (1lb) white marzipan. Roll two-thirds to a strip to fit round the cake sides, then press on and pinch together.
Roll out the remaining marzipan to fit the cake top, using the cake tin as a template. Lift on with the rolling pin and gently press into place. Press the edges to seal. There is no need to let the marzipan dry before icing the cake (below).