Mocha Layer Cake with Chocolate-Rum Cream Filling

This ultra-rich dessert is inspired by the classic Rigó Jancsi cake, named for the legendary Hungarian Gypsy violinist. Make it one day ahead to allow the flavors to meld.

Mocha Layer Cake with Chocolate-Rum Cream Filling

INGREDIENTS
Filling and Topping
  1. 4 cups whipping cream
  2. 1/4 cup (1/2 stick) unsalted butter
  3. 1/4 cup sugar
  4. 20 ounces semisweet chocolate, finely chopped; plus 2 ounces, chopped separately
  5. 1/3 cup dark rum
  6. 2 teaspoons vanilla extract

Syrup
  1. 1/4 cup water
  2. 2 tablespoons sugar
  3. 2 tablespoons dark rum

Cake
  1. 1 1/2 teaspoons vanilla extract
  2. 3/4 teaspoon instant coffee powder
  3. 2/3 cup cake flour
  4. 3 tablespoons unsweetened cocoa powder
  5. 1/2 teaspoon baking soda
  6. 3 large eggs, separated
  7. 3/4 cup sugar
  8. 1/4 teaspoon cream of tartar
  9. 1/4 teaspoon salt

PREPARATION
For filling and topping:
  • Stir first 3 ingredients in heavy large saucepan over medium-high heat until sugar dissolves and cream comes to simmer. Remove from heat. Add 20 ounces chocolate; whisk until melted and smooth. Whisk in rum and vanilla. Transfer 1 cup warm chocolate mixture to small bowl; whisk remaining 2 ounces chocolate into mixture in bowl and set aside for topping. Cover; let stand at room temperature. Transfer remaining chocolate mixture to large bowl to use as filling; chill until cold and thick, at least 6 hours and up to 1 day.
For syrup:
  • Stir water and sugar in small saucepan over low heat just until sugar dissolves. Remove from heat; mix in rum. Cover and let stand up to 1 day.