Vietnamese coffee is bold, dark and slightly bitter, which makes it a natural partner for mascarpone. In this version, the coffee does most of the work, so the cream does not need to be overly sweet.
Dip the sponge briefly in cooled coffee, then layer it with a light mascarpone mixture. Repeat, dust generously with cocoa and leave the tiramisu in the fridge overnight. By the next day, the layers become soft and settled while the coffee flavour stays clear. Serve it cold, preferably with another small coffee nearby.
