Prepare 2 quantities Sponge Cake batter and divide between 3 greased and lined jelly roll pans.
Bake at 425°F (220°C) for 10-12 minutes.
Remove cakes from pans while still warm.
Turn out onto clean wax paper, removing paper lining.
Carefully halve each cake lengthwise, giving 6 layers.
Spread each layer of cake with apricot jam.
Layer cake together.
Roll out almond paste to the size of the cake.
Place on top of cake.
Cover with foil or wax paper, weight down with a heavy wooden board and leave for 24 hours.
Cut the cake into 1 1/2 inch (3.5 cm) squares or shapes.
Beat icing sugar with water and rum till smooth.
Color icing as desired.
Coat cake squares in icing.
Place on cake rack to dry.
Pipe decorations with remaining icing and decorate with cherries, chocolate sprinkles, etc.
When dry, place each square in paper cupcake cases to serve.