Bittersweet Chocolate Mousse

Line heavy large baking sheet with parchment paper. Using round mousse ring as template, draw sixteen 3-inch circles on parchment paper. Turn parchment paper over. Spoon 1 generous teaspoonful melted chocolate into each circle. Using small offset spatula and staying within the lines, spread chocolate evenly over circles. Refrigerate until set. Transfer 8 chocolate discs to small container; cover and refrigerate. Spray insides of 8 rings with nonstick spray. Place rings atop remaining 8 chocolate discs on parchment paper; refrigerate.

Bring milk to simmer in heavy medium saucepan. Whisk egg yolks, 1/2 cup sugar and salt to blend in large bowl. Gradually whisk hot milk into yolk mixture. Return mixture to saucepan. Stir constantly over low heat until mixture thickens and instant-read thermometer registers 140 degrees F (do not boil). Remove from heat; stir in chocolate, whisking until smooth. Stir in brandy and vanilla. Transfer chocolate mixture to large wide bowl.

Using electric hand mixer with whisk attachment, beat egg whites in another large bowl until soft peaks form.* Gradually beat in remaining 1/4 cup sugar. Continue beating just until stiff peaks form. Stir spoonful of whites into slightly warm chocolate mixture to lighten. Using rubber spatula, fold remaining whites into chocolate mixture. Using same beaters, beat cream in same large bowl just until stiff peaks form. Fold whipped cream into chocolate mixture. Divide mousse equally among rings. Refrigerate overnight.

Using metal spatula, transfer mousse to plates. Place 1 reserved chocolate disc on top surface of each mousse. Using disc to keep mousse from moving, carefully slip rings from mousse. Using fine sieve, lightly dust each mousse with cocoa powder and serve.