Bittersweet Chocolate Marquise with Cherry Sauce

Ingredients

• 2 cups cherries fresh pitted halved
• 2.5 teaspoons cornstarch 
• 2 tablespoons dutch-processed cocoa powder unsweetened sifted
• 4 large egg yolk 
• 2 teaspoons brandy (clear cherry brandy)
• 1 tablespoon juice of lemon fresh
• 0.5 teaspoon lemon zest grated
• 10 ounces bittersweet chocolate unsweetened chopped (not )
• 0.3 cup sugar 
• 0.8 cup butter unsalted room temperature
• 1 tablespoon vanilla extract 
• 0.5 cup water 
• 1 cup whipping cream chilled

Equipment

• bowl
• sauce pan
• whisk
• double boiler
• hand mixer
• aluminum foil
• candy thermometer

Directions

1. Butter 8 1/2x5 1/2x3-inch glass loaf dish. Line dish smoothly with foil. Stir chocolate in top of double boiler over barely simmering water until smooth. Turn off heat. Using electric mixer, beat 1/2 cup butter in large bowl until fluffy. Beat in 1/4 cup sugar, then cocoa powder.
2. Whisk yolks, 1/4 cup water, 1/4 cup butter, and 1/4 cup sugar in metal bowl. Set over saucepan of simmering water (do not let bowl touch water).
3. Whisk constantly until candy thermometer registers 160°F, about 6 minutes.
4. Remove from over water. Using electric mixer, beat yolk mixture until thick and cool, about 5 minutes. Beat into cocoa mixture. Fold in warm chocolate and vanilla. Beat cream in another bowl until soft peaks form. Fold into chocolate mixture; spread in prepared dish. Cover and chill until firm, at least 4 hours. (Can be made 4 days ahead. Keep chilled.)
5. Stir all ingredients in medium saucepan over medium heat until sauce boils and thickens, about 5 minutes. Cool slightly. (Can be made 2 days ahead. Cover and refrigerate. Rewarm before serving.)
6. Turn marquise out onto platter; peel off foil.
7. Cut into 3/4-inch-thick slices.
8. Place 1 slice on each plate. Spoon warm cherry sauce over and serve immediately.