• Brew a strong cup of coffee, preferably espresso, and allow it to cool completely. This ensures the coffee is suitable for soaking the ladyfingers later.
• In a large mixing bowl, combine the egg yolks and ¼ cup (50 g) of sugar. Beat the mixture at medium-high speed using a stand or hand mixer for about 5 minutes. The result should be a thick, pale mixture that forms ribbons when the whisk is lifted, indicating it is adequately aerated.
• To this yolk mixture, add the chilled mascarpone and vanilla extract. Mix at medium speed for roughly 3 minutes until the blend achieves a creamy yet sturdy consistency. The mixture should hold its shape when lifted with a spoon but remain pliable enough to spread.
• In a separate clean bowl, whip the egg whites using clean whisks until frothy. Gradually add the remaining ½ cup (100 g) of sugar while continuing to beat. After approximately 5 minutes, the egg whites should form stiff peaks that maintain their shape when the whisk is removed. Be cautious not to over-whip, as this can cause the whites to become grainy.
• Carefully fold half of the beaten egg whites into the mascarpone mixture. Use a gentle folding motion to preserve the airiness. Once incorporated, add the remaining egg whites and fold until the mixture is smooth and uniform. Avoid overmixing to prevent deflating the mousse-like texture.

Assembly

• Ensure the coffee has cooled to room temperature or is slightly warm. Dip each ladyfinger into the coffee, submerging for no more than 1 second per side to avoid oversaturation. Line the base of a 9x13-inch dish with a single layer of dipped ladyfingers, breaking them as needed to fill any gaps.
• Spread half of the mascarpone cream over the ladyfingers, smoothing it evenly to the edges of the dish.
• Repeat the process with the remaining ladyfingers, dipping them in coffee and layering them over the mascarpone cream. Ensure the layer is snug with no visible gaps.
• Finish by spreading the remaining mascarpone mixture over the top layer of ladyfingers. Smooth the surface for a neat presentation.
• Cover the dish tightly with plastic wrap, ensuring the wrap does not touch the surface of the cream. Refrigerate the tiramisu for at least 8 hours, preferably overnight, to allow the flavors to meld and the dessert to set.
• Before serving, generously dust the top with cocoa powder for a classic finish. Slice into portions and enjoy!