Prepare the Egg Mixture:

• In a medium saucepan, whisk together the 6 egg yolks and 3/4 cup granulated sugar until well combined.
• Add the 2/3 cup milk to the saucepan and cook over medium heat, stirring constantly until the mixture thickens slightly (about 5-7 minutes). Do not let it boil. Once thickened, remove from heat and let it cool slightly.

Beat the Cream:

• In a separate large mixing bowl, use an electric mixer to beat 1 1/4 cups of heavy cream until stiff peaks form. This will add lightness to the tiramisu.

Combine Mixtures:

• Once the egg mixture has cooled, gently fold in 1 cup of mascarpone cheese until smooth. Then, carefully fold in the whipped cream until fully combined. Be gentle to maintain the airy texture.

Prepare the Coffee Mixture:

• In a shallow dish, combine the cooled strong brewed coffee and the optional coffee liqueur.

Assemble the Tiramisu:

• Quickly dip each ladyfinger into the coffee mixture, making sure not to soak them—just a quick dip is sufficient.
• Lay half of the dipped ladyfingers in a single layer at the bottom of a rectangular or square serving dish.

Layer the Filling:

• Spread half of the mascarpone mixture over the layer of ladyfingers, smoothing it out evenly with a spatula.

Repeat Layers:

• Add another layer of dipped ladyfingers on top of the mascarpone mixture, followed by the remaining mascarpone mixture. Smooth the top layer again.

Chill:

• Cover the dish with plastic wrap and refrigerate for at least 4 hours, or overnight if possible. This allows the flavors to meld and the dessert to set.

Serve:

• Before serving, dust the top generously with unsweetened cocoa powder using a fine mesh sieve. Cut into squares or scoop into bowls and enjoy your delicious homemade tiramisu!