Boil the coffee, let it cool a bit and mix it with a dash of rum.
In a bowl, whip the whipped cream until stiff. Mix in curd cheese, macarpone and powdered sugar. Peel the bananas and cut into slices.
Dip the biscuits in the coffee-rum mixture and layer in a baking dish. Cover with a layer of mascarpone cream, top with banana slices and biscotti. Continue layering until all ingredients are used (finishing with a layer of mascarpone cream).
Refrigerate for at least 2 hours and sprinkle with cocoa powder before serving.