Bittersweet Chocolate Mousse Brownies

INGREDIENTS

• 6 tablespoons unsalted butter
• 1 (1 ounce) square unsweetened chocolate
• 1/2 cup white sugar
• 1 egg
• 1/4 teaspoon vanilla extract
• 1/3 cup all-purpose flour
• 1/8 teaspoon baking soda
• 1/8 teaspoon salt
• 4 (1 ounce) squares bittersweet chocolate, chopped
• 3 tablespoons strong brewed coffee
• 3 eggs
• 3/4 cup heavy whipping cream
• 1/3 cup heavy whipping cream
• 1 tablespoon confectioners' sugar