Dissolve the sugar in the espresso/coffee and pour into a shallow long pan to cool slightly. Mix in the rum or coffee liqueur.
Make a game plan for assembling your ladyfingers. Typically, the bottom layer will go one way in the pan, and the top layer will go the opposite. You can break or cut them as needed to fit into your pan(s).
Once your game plan is ready, start soaking your ladyfingers in the coffee mixture and assembling your tiramisu. A thin layer of the cream mixture on the bottom, then a layer of soaked ladyfingers, another thin layer of cream, then another cross-stacked layer of soaked ladyfingers.
Top with a final layer of cream and refrigerate for four to 24 hours.
Remove from the refrigerator and dust lightly with cocoa powder. You can cut and plate portions (similar to cutting brownies, but much more fragile), then grate some chocolate onto the top. Serve and enjoy!