PREPARE THE EGG YOLK MIXTURE:

1. Set Up Double Boiler: Fill a medium saucepan with 1-2 inches of water and bring to a gentle simmer over medium heat. Place a heat-safe glass or metal bowl on top, making sure the bottom doesn’t touch the water.
2. Combine Yolks and Sugar: Separate your eggs, placing yolks in the heat-safe bowl and whites in a separate large clean bowl (save for later). Add ½ cup sugar to the yolks and whisk vigorously for about 1 minute until the mixture is pale yellow and slightly thickened.
3. Heat the Mixture: Place the bowl over the simmering water (creating your double boiler). Whisk constantly for 5-8 minutes until the mixture thickens, becomes fluffy, and reaches 160°F on an instant-read thermometer. It should coat the back of a spoon and form ribbons when you lift the whisk. This step pasteurizes the eggs for food safety.
4. Cool Down: Remove the bowl from heat and continue whisking for another minute to cool slightly. Let it cool to room temperature, whisking occasionally, about 10-15 minutes. You can speed this up by setting the bowl over an ice bath and whisking constantly.

MAKE THE MASCARPONE CREAM:

5. Beat Mascarpone: In a large bowl, beat the room-temperature mascarpone cheese with an electric mixer on medium speed for 1-2 minutes until smooth and creamy with no lumps.
6. Combine with Egg Yolks: Once the egg yolk mixture has cooled to room temperature, add it to the mascarpone along with the vanilla extract. Beat on medium speed for 2-3 minutes until completely smooth, light, and fluffy. Set aside.
7. Whip the Cream: In another bowl, whip the cold heavy cream with clean beaters on medium-high speed until stiff peaks form, about 3-4 minutes. The cream should hold its shape firmly.
8. Whip the Egg Whites: In the bowl with your reserved egg whites, add a pinch of salt and beat on medium speed until foamy. Gradually add the remaining ¼ cup sugar while beating, then increase speed to high and whip until stiff, glossy peaks form, about 3-5 minutes. Don’t overbeat or they’ll become grainy.
9. Fold Everything Together: Gently fold the whipped cream into the mascarpone mixture using a rubber spatula, using wide sweeping motions from the bottom up. Then gently fold in the whipped egg whites in two additions. Fold just until no white streaks remain—overmixing will deflate the airiness. The mixture should be light, fluffy, and cloud-like.

PREPARE COFFEE MIXTURE:

10. Mix Coffee Dipping Liquid: In a shallow dish or pie plate, combine the cooled espresso or coffee, coffee liqueur (or chosen alcohol), and 2 tablespoons sugar. Stir until the sugar dissolves completely. Taste and adjust sweetness if needed.

ASSEMBLE THE TIRAMISU:

11. First Layer of Ladyfingers: Working with one cookie at a time, quickly dip a ladyfinger into the coffee mixture for about 1-2 seconds per side. You want them moistened but not soggy—they should still hold their shape. Immediately place the dipped ladyfinger in your 9×13 inch dish. Repeat until you have a complete layer covering the bottom (you’ll use about 20-24 cookies depending on how you arrange them). It’s okay if you need to break some cookies to fill gaps.
12. First Layer of Cream: Spread half of the mascarpone cream mixture over the ladyfinger layer, using a spatula to spread it evenly all the way to the edges. Smooth the top.
13. Second Layer of Ladyfingers: Repeat the dipping process with remaining ladyfingers, creating a second complete layer over the cream. You may need to trim or break cookies to fit perfectly.
14. Final Cream Layer: Spread the remaining mascarpone cream over the second layer of ladyfingers, smoothing it into an even layer. Make sure you cover all the cookies completely.
15. Dust with Cocoa: Using a fine-mesh sieve, generously dust the entire top surface with unsweetened cocoa powder. Create an even layer—don’t be shy with it! If desired, add chocolate shavings for extra elegance.

CHILL:

16. Refrigerate: Cover the dish tightly with plastic wrap (you can press it gently on the surface or tent it just above to avoid disturbing the cocoa). Refrigerate for at least 4 hours, but preferably overnight (8-12 hours) for the best flavor and texture. The wait is worth it as the flavors meld and the cookies soften perfectly.

SERVE:

17. Slice and Serve: When ready to serve, cut into 12 squares using a sharp knife (dip the knife in hot water and wipe clean between cuts for the cleanest slices). Dust each piece with an additional sprinkle of cocoa powder if desired. Serve chilled and enjoy the compliments!