unsweetened cocoa powder, for dusting(Dutch processed preferred, such as Hershey's Special Dark)
In the bowl of a stand mixer, whip the egg whites into soft peaks (white and foamy but not yet holding a peak). Slowly add ½ cup of sugar and continue to whip until stiff peaks form (a peak will stand straight up in a point when the whisk attachment is held up). Transfer the egg whites to another bowl.
In the same bowl, using the same whisk attachment, beat the egg yolks and ½ cup of sugar until thick and lighter in color, approximately 2-3 minutes. When the whisk is lifted from the bowl, the yolks should leave a ribbon-like trail. Add the mascarpone cheese, 1 tablespoon of the coffee, and 2 tablespoons of the amaretto (or liqueur of choice) and continue to beat until completely smooth and thick, 1-2 more minutes.
Fold ⅓ of the egg whites into the egg yolk mixture to lighten, then add the rest of the egg whites and continue to fold until smooth and light. Set aside.
In a wide, shallow bowl, mix together the espresso or coffee, the rest of the amaretto (¼ cup), and the rest of the sugar (½ cup).
Dip half the ladyfingers, top and bottom, quickly into the coffee mixture and arrange onto the bottom of an 11 by 7-inch baking dish. If you don't have this size baking dish, you can use a 9 by 13-inch dish, but the finished tiramisu won't be as tall.
Scoop half of the cream mixture onto the ladyfingers and spread into an even layer. Top with the other half of the ladyfingers that have been quickly dipped in the coffee syrup.
Top the final layer of ladyfingers with the rest of the cream mixture and use an offset spatula to smooth the top evenly. Cover with plastic wrap and refrigerate overnight.
When ready to serve, scoop a small amount (1-2 tbsp) of cocoa powder into a small sieve and sift over the entire surface of the tiramisu. Cut into large squares and use a spatula to remove from pan. Serve cold. Tiramisu will keep in the refrigerator, well covered, for 2-3 days.