Whisk the cold mascarpone cheese on medium speed for 30-60 seconds until it becomes creamy, then set it aside.

In a separate heatproof bowl, combine the egg yolks and sugar. Boil 1-2 inches of water in a saucepan, then reduce the heat to the lowest setting. Place the bowl with the egg yolks and sugar on top of the saucepan, ensuring that the water doesn't touch the bottom of the bowl. Whisk on medium-high speed for exactly 2 minutes, then remove from heat.

Pour the egg yolk and sugar mixture into the mascarpone cheese. Add the salt and vanilla extract, then whisk on medium speed until combined (be careful not to overmix, as this could make the mixture grainy).

In another bowl, whip the cold heavy cream until stiff peaks form (don’t overwhip).

Add the whipped cream to the mascarpone mixture in 2-3 additions, gently folding with a rubber spatula to preserve the airiness.

Whisk the cold mascarpone cheese on medium speed for 30-60 seconds until creamy, then set it aside.

In a separate heatproof bowl, combine the egg yolks and half of the sugar. Boil 1-2 inches of water in a saucepan, then reduce the heat to the lowest setting. Place the bowl with the egg yolks and sugar on top of the saucepan, ensuring the water does not touch the bowl’s bottom. Whisk on medium-high speed for exactly 2 minutes, then remove from heat.

Pour the egg yolk and sugar mixture into the mascarpone cheese. Add the salt and vanilla extract, then whisk on medium speed until combined (again, avoid overmixing to prevent graininess).

In a clean bowl, add the egg whites and the remaining sugar. Place the bowl over the saucepan with boiling water and whisk on medium-high speed with a clean whisk until the mixture reaches 160°F. Remove from heat and continue whisking until a glossy, stiff meringue forms.

Fold the meringue into the mascarpone mixture in 2-3 additions, gently incorporating it with a rubber spatula to avoid deflating the meringue.

Pour the coffee into a wide bowl. Dip each ladyfinger briefly into the coffee (a quick dip on each side, or up to 1-2 seconds per side) and create a layer of soaked ladyfingers in the bottom of a 7x11" rectangular dish.

Spread half of the mascarpone cream evenly over the ladyfingers.

Repeat with another layer of soaked ladyfingers, followed by the remaining mascarpone cream, which can also be piped on in dollops for a decorative touch.

Cover and refrigerate for at least 4 hours, or overnight.

When ready to serve, sift cocoa powder evenly over the top of the tiramisu. Cut into slices and serve!