In a small saucepan combine the chocolate and water.
Slowly heat over medium-low heat, frequently whisking, until the chocolate is melted.
Carefully separate the egg whites from their yolks, placing the whites into the bowl of a stand mixer or large mixing bowl and the yolks into a small bowl. Make sure you don't get any yolk into the egg whites or the whites won’t whisk into fluffiness.
Slowly, while whisking constantly, add the egg yolks, vanilla, and pinch of salt to the melted chocolate.
Pour the chocolate mixture into a medium-sized mixing bowl.
Using a stand mixer, hand mixer, or whisk, beat the egg whites with the beaters until stiff peaks form. Add in the coconut sugar if using (see notes).
Gently fold half of the egg whites into the chocolate with a rubber spatula.
Fold in the remaining egg whites until the mixture is relatively uniform.
If using heavy cream, wash and dry the mixing bowl, making sure to rinse it with cold water so the bowl stays cold.
Whisk the cream until it becomes whipped cream and soft peaks form.
Fold the whipped cream into the chocolate/egg white mixture.
Pour or spoon the mixture into serving dishes.
Refrigerate for 4 hours before serving.
To serve, top with a dollop of whipped heavy whipping cream and garnish with dark chocolate shavings (or other toppings) if desired.
Notes
The key to making a fluffy chocolate mousse is to fold the egg whites and chocolate together gently, and also the whipped cream if using. Don’t overmix!
I don’t have much of a sweet tooth, so this mildly sweet dessert is perfect for me. However, if you like your desserts a little sweeter, slowly add a few tablespoons of coconut sugar to the egg whites while they're whisking.