Pour the orange liqueur over the fruit and let it stand covered for about 1 hour. In the meantime, grate half of the chocolate very finely on a kitchen grater, cut the other half into very small pieces.
Whip 250 g whipped cream with the whisks of the hand mixer until very stiff. Then stir in the icing sugar. Fill cream in equal parts into two bowls. Drain the fruits well, catching the liquid and add to one half of the cream with the finely grated chocolate.
Mix the chocolate pieces into the other cream portion. Chill both. Put the sugar with 50 ml water into a pot and boil it down at low heat while stirring constantly to a thin syrup.
Allow to cool and mix with 2 cl of the orange liqueur collected. Cut the lower sponge cake base into six equally sized cake pieces and line a bowl lined with aluminium foil (1 litre capacity) with them, cutting a little at a time.
Soak the sponge cake pieces abundantly with the syrup. First fill the fruit cream and then the chocolate cream into the bowl, smooth it down. Cover with the second base cut to the size of the bowl and press down lightly.
(use the leftover sponge cake for other purposes). Also sprinkle with syrup. Put the sponge bomb in the refrigerator for 5 hours. Whip the remaining cream very stiff before serving. Turn the dessert out of the tin, remove the foil and spread with 2/3 of the cream.
Put the rest of the cream in a piping bag with a star-shaped spout and decorate the sponge cake bomb with cream patches and quartered cherries. Makes about 12 pieces.