Whip together the egg yolks and half (1/4 cup) of the sugar in a medium bowl using an electric mixer. Whip until the mixture is a pale yellow color and has tripled in volume. A small ribbon of the mixture should drop from the whisk attachment when you lift it from the bowl. Transfer your mixture to a large bowl, then clean out the medium bowl to be used in the next step.

In the medium bowl, whip together the cream and the rest of the sugar (remaining 1/4 cup) until you have soft-medium peaks. Add the mascarpone and keep whipping until you have a soft and spreadable mixture with medium peaks. Fold the mascarpone mixture gently into the sweetened egg yolks until combined.

Brew 2 rich cups of Butter-Nut® espresso by stirring 3 to 4 teaspoons Butter-Nut® Instant Espresso into 12 ounces of hot water. Pour the espresso into a shallow bowl and allow it to cool until warm. If you are using liqueur, stir it into the espresso now.

Dust the bottom of a 2-quart baking dish (or an 8×8 inch dish or even a 9-inch round cake pan) with 1 tablespoon cocoa powder, using a sifter.

Quickly dip the ladyfingers, one at a time, into the espresso mixture. Be careful not to let the ladyfingers get too soggy, as they will soak up the espresso quite quickly. You may wish to test your dipping method out first to see exactly how long you can soak them before they get soggy. Place the ladyfingers rounded side up on the bottom of your baking dish.

NOTE: If you find that they are dissolving too quickly, you can use a pastry brush or even a turkey baster to squirt the espresso directly on them in the pan. If using this method, you will want to drizzle approximately 2 teaspoons espresso over each lady finger, covering completely. The cookies will soak up moisture from the egg and mascarpone mixture as well, but it is important, if you are using this drizzling method, that you let the completed cake rest in the fridge overnight- otherwise your ladyfingers will not soak in the moisture and be hard.

Using half of the ladyfingers, you should have an even layer spread throughout the bottom of the dish. You can break the ladyfingers in half as needed to fill any gaps near the sides of the dish. Spread your mascarpone mixture onto the top of the ladyfingers in one even layer. Create a second layer of ladyfingers on top of the first one using the remaining half of the espresso-soaked ladyfingers, spreading the mascarpone mixture on top of this second layer as well.

Sprinkle the cocoa powder onto the top of the top layer and top with shaved chocolate, as desired.

Cover the dish with plastic wrap and chill in your refrigerator for about 4-6 hours. If you have the patience to wait 24 hours, chilling the tiramisu longer will result in an even better consistency and flavor.