For the banana tiramisu, whisk the uncooled Qimiq Classic until smooth. Add the mascarpone, milk, instant coffee, sugar, vanilla sugar, Amaretto and 1 mashed banana. Fold in the whipped cream.
Drizzle the sponge cake with rum-coffee mixture and fill into glasses in layers with the cream. Finish with the cream and refrigerate for at least 4 hours.
Dust with cocoa powder before serving.