Step 1

First, make the Earl Grey tea concentrate. Bring the water to a boil in a heavy-bottomed, medium saucepan over high heat. Add the Earl Grey tea and immediately reduce the heat to medium-low. Simmer for 10 minutes. Meanwhile, place the sugar for the tea concentrate in a medium, heatproof bowl.After 10 minutes, taste the concentrate—you want it to have a really strong Earl Grey flavor, almost to the point of being bitter. If it’s not quite there, simmer for another 5 minutes. When the concentrate is ready, place a fine-mesh sieve over the bowl with the sugar and strain the concentrate into the bowl. Gently press on the tea leaves or bags with a heatproof spatula and discard them. Whisk the concentrate to dissolve the sugar, then whisk in the vanilla and salt.Set on a wire rack to cool slightly while you make the mascarpone whipped cream.

Step 2

Make the mascarpone whipped cream. In the bowl of a stand mixer fitted with the whisk attachment, whisk the cream on medium-high speed until soft peaks form, 1 to 2 minutes.Turn the mixer off and add the mascarpone and vanilla for the whipped cream all at once. Scrape down the bottom and sides of the bowl with a rubber spatula, then whisk the mascarpone and vanilla into the whipped cream on medium speed until combined, about 30 seconds.Transfer the whipped cream to a medium bowl.

Step 3

Whisk the egg yolks and sugar, then fold in the whipped cream. Combine the egg yolks, sugar, and salt for the mascarpone whipped cream in the stand mixer bowl (there's no need to clean the bowl!). Beat on medium-high speed until light, fluffy, and doubled in volume, about 5 minutes.Scoop half of the whipped cream over the egg mixture and fold it in with a rubber spatula. Repeat with the remaining whipped cream and fold it in until just combined. At this point, it will be a very light and fluffy cream.

Step 4

Assemble the Earl Grey tiramisu. Working with one ladyfinger at a time, dip a ladyfinger in the Earl Grey tea concentrate, and turn to coat. Quickly place it in the pan to arrange a single layer of cookies at the bottom of the pan. If using an 8-inch square pan, you’ll end up using around 13 ladyfingers. You may need to slice or break the ladyfingers to fit them into the pan.Scoop half (around 12 ounces or 340 grams) of the mascarpone whipped cream over the ladyfingers and use an offset spatula to spread it evenly over the cookies.Repeat the process of soaking the remaining ladyfingers, and topping them with the remaining mascarpone whipped cream to make the final 2 layers of the Earl Grey tiramisu.

Step 5

Chill the Earl Grey tiramisu. Loosely cover the tiramisu with plastic wrap. Refrigerate for at least 8 hours, preferably overnight.

Step 6

Serve and store. Serve chilled. The tiramisu will keep, tightly covered in plastic wrap or sliced in an airtight container, for up to 3 days in the refrigerator.