1 x 20cm round or 18cm square Christmas cake (see 'Goes well with', below)
4 tbsp raspberry or apricot jam, warmed and sieved
500g pack marzipan
icing sugar, for dusting
1¼kg pack ready-to-roll white icing
1 egg white, frothed with a fork, or a little thin, runny icing made with icing sugar and water
preserving sugar or granulated sugar
a little edible glitter, if you have it
Sit the cake on a cake board or flat plate. Brush all over with a little of the jam. Roll out the marzipan on an icing sugar-dusted surface until large enough to cover the sides and top of the cake - use string to help you measure. Cover the cake and trim the excess marzipan from the bottom. Brush with jam again, knead 850g of the white icing until smooth and pliable, then roll out as you did you for the marzipan ensuring it is large enough to cover the top and sides. Lift onto the cake. Smooth the icing down and around the sides, trimming excess from the bottom, as before. Smooth out any marks with the flats of your hand, rubbing the icing to buff it to a shine.
Roll out the rest of the white icing and cut out a few snowflakes. Brush one side with a little egg white or runny icing, then dip this side into the preserving or granulated sugar to coat. Sprinkle on glitter, if using, then use more egg white or icing to stick randomly onto the cake. Leave to set for a few hrs before cutting.