Tiramisù

1. Stir coffee, 5 tablespoons rum, and espresso in wide bowl or baking dish until espresso dissolves; set aside.
2. Using stand mixer fitted with whisk, whip egg yolks on low speed until just combined. Add sugar and salt and whip on medium-high speed until pale yellow, 1-1⁄2 to 2 minutes, scraping down bowl once or twice. Add remaining 4 tablespoons rum and whip on medium speed until just combined, 20 to 30 seconds; scrape down bowl. Add mascarpone and whip on medium speed until no lumps remain, 30 to 45 seconds, scraping down bowl once or twice. Transfer mixture to large bowl and set aside.
3. In now-empty mixer bowl, whip cream on medium-low speed until foamy, about 1 minute. Increase speed to high and whip until stiff peaks form, 1 to 3 minutes. Using rubber spatula, fold one-third of whipped cream into mascarpone mixture to lighten, then gently fold in remaining whipped cream until no white streaks remain. Set mascarpone mixture aside.
4. Working with one at a time, drop half of ladyfingers into coffee mixture, roll to coat, remove, and transfer to 13 by 9-inch glass or ceramic baking dish. (Do not submerge ladyfingers in coffee mixture; entire process should take no longer than 2 to 3 seconds for each cookie.) Arrange soaked cookies in single layer in baking dish, breaking or trimming ladyfingers as needed to fit neatly into dish.
5. Spread half of mascarpone mixture over ladyfingers with spatula, spreading mixture to sides and into corners of dish, then smooth surface. Place 2 tablespoons cocoa in fine-mesh strainer and dust cocoa over mascarpone.
6. Repeat dipping and arrangement of ladyfingers; spread remaining mascarpone mixture over ladyfingers and dust with remaining 1-1⁄2 tablespoons cocoa. Wipe edges of dish clean with paper towel. Cover with plastic wrap and refrigerate for at least 6 hours or up to 24 hours. Garnish with grated chocolate, if using; cut into pieces and serve chilled. (Tiramisù can be refrigerated for up to 1 day.)

TIRAMISÙ WITH FRANGELICO AND ORANGE
Amaretto can be substituted for the Frangelico, and brandy and even whiskey can stand in for the dark rum.
Reduce dark rum to 5 tablespoons total, adding 3 tablespoons rum, plus 3 tablespoons Frangelico, to coffee mixture in step 1, and 2 tablespoons rum plus 3 tablespoons Frangelico to whipped egg yolk mixture in step 2. Whip 1⁄2 teaspoon grated orange zest with mascarpone in step 2.

TIRAMISÙ WITH SAMBUCA AND LEMON
Omit dark rum. Stir in 2 tablespoons Sambuca with coffee and espresso in step 1. Add 2 tablespoons sambuca to whipped egg yolk mixture in step 2. Whip 1-1⁄4 teaspoons minced grated lemon zest with mascarpone in step 2.

TIRAMISÙ WITHOUT RAW EGGS
This recipe involves cooking the yolks in a double boiler, which requires a little more effort and makes for a slightly thicker mascarpone filling, but the results are just as good as with our traditional method. You will need an additional 1⁄3 cup heavy cream.
In step 2, add 1⁄3 cup cream to egg yolks after sugar and salt; do not whisk in rum. Set bowl with egg yolks over medium saucepan filled with 1 inch of barely simmering water and cook, constantly scraping along bottom and sides of bowl with heatproof rubber spatula, until mixture coats back of spoon and registers 160 degrees, 4 to 7 minutes. Remove from heat and stir vigorously to cool slightly, then set aside and let cool completely, about 15 minutes. Whisk in remaining 4 tablespoons rum until combined. Using stand mixer fitted with whisk, whip egg yolk mixture and mascarpone together on medium speed until no lumps remain, 30 to 45 seconds. Transfer mixture to large bowl and set aside. Continue with recipe from step 3, using full amount of cream specified (3⁄4 cup).