Separate egg yolks and egg whites. Beat the yolks with the sugar until light and white.
Add the mascarpone and one tablespoon of black tea, whisk again to remove any lump of mascarpone.
Whip egg whites until stiff and fold them gradually into the mascarpone cream.
Chop dark chocolate with a knife into small pieces, not too homogeneous: lucky those who will find some bigger chips!
Make the tiramisu alternating layers of mascarpone cream, chopped dark chocolate and lady fingers quickly soaked in tea. Finish with a dusting of cocoa powder and let it sit in the fridge for a few hours before serving.