Prepare the Mocha Mousse. Heat 1-inch of water in the bottom half of a double boiler over medium high heat. Place 14 ounces semisweet chocolate, 4 ounces unsweetened chocolate, 1/2 cup water, 4 tablespoons of instant coffee, and 2 tablespoons cocoa in the top half of the double boiler. Tightly cover the top with film wrap. Heat for 6 to 7 minutes, remove the film wrap, and stir the mixture until smooth. Keep at room temperature until needed.

Place egg whites in the bowl of an electric mixer fitted with a balloon whip. Whisk on high speed until soft peaks form, about 1 minute. Continue to whisk while gradually adding 2 tablespoons of sugar. Whisk until stiff, about 30 seconds.

Whip 3/4 cup heavy cream in a well-chilled stainless-steel bowl until stiff. Fold 1/4 of the egg whites into the melted chocolate mixture, then fold in the whipped cream now fold in the remaining egg whites. Hold the mocha mousse at room temperature.