Add roughly 1 inch of water to a small pot, and bring it to a boil over high heat on the stove. Reduce the heat to low, letting the water simmer.

In a medium bowl, add the egg yolks and sugar. Whisk to combine.

Place the pot on top of the saucepan, making sure it does not touch the water. Continue to whisk constantly for 10 minutes or until the mixture thickens and increases in volume.

Remove the bowl from the heat, and add the vanilla. Continue to whisk until the zabaglione cools down and is thick and bright yellow.

Add the mascarpone, and mix to combine. Be careful not to overmix, as this can cause curdling!

In a separate large bowl, add the heavy whipping cream. Using an electric mixer, beat the cream on low, slowly increasing the speed until stiff peaks form.

Gently fold the whipped cream into the mascarpone mixture.

In a bowl, combine the warm espresso or coffee and sugar. Set aside to cool.

Dip the ladyfingers into the cool coffee just long enough to coat them with the liquid.

Arrange the ladyfingers in a 9-inch square baking dish.

Spoon half the mascarpone cream filling on top, spreading it out evenly.

Repeat, adding a second layer of ladyfingers followed by the rest of the mascarpone filling.

Refrigerate for at least 4 hours or up to overnight.

Dust with cocoa powder, and enjoy!

Store covered in the fridge for up to 2-3 days.