Pasticceria Gollini in Vignola, Italy, not far from Modena, is home to the sumptuous flourless chocolate cake known as torta Barozzi. Created in 1886 by pastry chef Eugenio Gollini and named for Jacopo Barozzi da Vignola, a 16th-century architect, the much-loved sweet continues today to be produced according to a closely guarded secret recipe. Impostor recipes abound, as professional and home bakers alike have attempted to re-create the dessert, and we ourselves set out to devise a formula. It’s well known that torta Barozzi is made without wheat flour (and is therefore gluten free). Instead, a combination of ground peanuts and almonds—along with whipped egg whites—deliver a structure that’s somehow rich and dense yet remarkably light. We found that we could skip the peanuts, as almond flour alone worked well. To achieve a complex chocolatiness, we use both cocoa powder and bittersweet chocolate (ideally, chocolate with about 70 percent cocoa solids). Instant espresso powder accentuates the deep, roasty, bitter notes and a dose of dark rum lifts the flavors with its fieriness. Serve with lightly sweetened mascarpone or whipped cream, or with vanilla gelato.