Chocolate Espresso Kahlua Tart

Martha Stewart Living, 2004

Makes 8 servings

    CRUST:                                                         
    9 ounces hazelnuts                                             
    1 1/3 cups finely ground chocolate wafers (about 22)           
    1/2 teaspoon instant espresso powder                           
    1/4 teaspoon salt                                              
    10 tablespoons unsalt butter melted, cooled slightly         
  
    MOUSSE:                                                        
    1/2 cup kahlua                                                 
    1/2 cup unsweetened cocoa                                      
    2 lg. eggs separated                                           
    1 teaspoon instant espresso powder                             
    Pinch salt                                                     
    4 ounces bittersweet chocolate                                 
    4 tablespoons unsalt butter                                    
    1 cup heavy cream                                              
    6 tablespoons sugar                                            

CRUST:
Preheat oven to 375°. Toast hazelnuts in oven on a rimmed baking sheet until skins split and flesh turns deep golden brown, 10 to 12 minutes. When cool enough to handle, rub nuts in a clean kitchen towel to remove skins (some will remain). Let cool completely. Finely grind in a food processor. Reduce oven temperature to 325°.

Stir together nuts, cookie crumbs, espresso powder, salt, and butter. Press onto bottom and up sides of an 11-inch round tart pan with a removable bottom. Refrigerate until firm, about 30 minutes.

Bake tart shell on a baking sheet until firm to the touch, about 20 minutes. Let cool completely on a wire rack.

MOUSSE:
Whisk liqueur, cocoa, egg yolks, espresso powder, and salt in a medium bowl. Melt chocolate and butter in a heatproof bowl set over a pan of simmering water. Whisk in liqueur mixture. Cook, whisking, until mixture is thickened and registers 160° on an instant-read thermometer. Let cool completely.

Beat cream just to stiff peaks; set aside. Whisk egg whites and sugar in the heatproof bowl of an electric mixer set over a pan of simmering water. Cook, whisking, until sugar is dissolved and mixture registers 140° on thermometer.

Fit mixer with the whisk attachment; transfer bowl with meringue to mixer. Starting on medium speed and gradually increasing to high, beat meringue until shiny and cool. Using a rubber spatula, fold chocolate mixture and then whipped cream into meringue. Spread in tart shell. Refrigerate until set, about 1 hour.