Prepare the Mascarpone Cream

Option 1: Using Heavy Cream

1. In a medium bowl, beat mascarpone cheese until creamy and smooth; set aside.
2. Whisk egg yolks and sugar in a heat-proof bowl. Place over simmering water (double boiler) and whisk for 2 minutes until thickened. Remove from heat.
3. Combine egg yolk mixture with mascarpone. Add vanilla and a pinch of salt, mixing gently.
4. Whip cold heavy cream to stiff peaks and fold it into the mascarpone mixture in batches for a fluffy texture.

Option 2: Using Egg Whites for Meringue

1. Follow steps 1–3 above.
2. Whisk egg whites and sugar in a heat-proof bowl over simmering water until the mixture reaches 160°F. Remove and beat to stiff, glossy peaks.
3. Fold the meringue into the mascarpone mixture gently to retain the airy consistency.

2. Assemble the Tiramisu

1. Prepare the Coffee: Pour the cooled coffee into a shallow bowl.
2. Layer the Ladyfingers: Dip each ladyfinger quickly into the coffee (1–2 seconds per side). Arrange a single layer in a 7×11″ dish.
3. Spread the Cream: Spread half the mascarpone mixture over the ladyfingers. Repeat with another layer of dipped ladyfingers and top with the remaining cream.
4. Chill: Cover with plastic wrap and refrigerate for at least 4 hours or overnight to allow the flavors to meld.

3. Serve

1. Before serving, dust the top generously with cocoa powder using a fine sieve.
2. Slice into squares and serve chilled.