For the coffee bomb, dissolve the coffee in hot or cold water. Separate eggs, whisk coffee with yolks, sugar and vanilla sugar until foamy.
Beat egg whites until stiff, then whip whipped cream until stiff. Fold beaten egg whites and half of the whipped cream into the coffee-egg mixture.
Cut biscuits in half, sprinkle with rum and line a bowl with them. Pour in coffee cream and place in freezer.
Freeze for 2 hours, turn out the coffee bomb and decorate with the remaining whipped cream.