Old-School Tiramisu

Lightly oil a 9x5" loaf pan and line with plastic wrap, leaving plenty of overhang. Whisk coffee, rum, salt, and 1 Tbsp. sugar in a shallow dish until sugar and salt dissolve. Chill until ready to use.

Whisk cream and mascarpone in a medium bowl just until smooth. Set aside.

Pour water into a large saucepan to come 2" up the sides and bring to a simmer. Combine egg yolks, remaining 1/3 cup sugar, and 2 Tbsp. water in a medium heatproof bowl. Set bowl over pan and reduce heat to low so water is at a bare simmer. Using an electric mixer (or a large whisk and a friend to fill in when your arm cramps), beat mixture on medium-high until eggs triple in volume and are extremely pale yellow and mixture forms a slowly dissolving ribbon when drizzled over itself in bowl, 5–7 minutes. Remove bowl from heat.