Make the espresso coffee, and mix with 2 Tbsp sugar while hot, then add some water (to end up with 6 oz/177 ml). The end result should be to your liking; stronger or weaker as desired. Set up a double boiler (if you don’t have one) by placing a glass bowl over a little hot water (the bowl should not touch the water) over low heat. Beat the egg yolks and rest of the sugar off the heat for a few minutes, then transfer the bowl over to the barely simmering water in the pot.
Continue beating until the temperature reaches 150 degrees F, or 65 C. Beat for 2 more minutes, then allow to cool, stirring now and then so that it doesn’t create a skin.
Add the mascarpone cheese to the egg and sugar mixture and beat until well combined.
Pour some cold/room temperature coffee into a bowl and begin dipping the biscuits, turning over once.
Place each dipped cookie into the pan or plate until you have 6 making the bottom layer.
Cover the soaked cookies with one half of the egg and mascarpone mixture and continue to dip the rest of the cookies into the coffee and make another layer on top of the egg mixture.
Top with the rest of the egg and mascarpone cream to cover all the ladyfinger cookies, cover with cling film, and refrigerate for at least 4 hours, but preferably overnight.
When ready to serve, remove from the refrigerator and dust generously with unsweetened cocoa. Serve immediately once removed from the fridge.