First of all, in order to make it a pie like the picture above, you need pie crust.
I call it chocolate mouse cup pie.
I created a sweeter and more crunchy variant of the usual pie crust. The Pie Crust Crumb Cookie.

Now for the mousse...
The picture above is made with semi sweet chocolate chips.
The step by step here is made with Lindt milk chocolate.
It doesn't matter which chocolate you use.
Use what you like the most.Even dark or white

Ingredients
1 cup of semisweet chocolate chips (or chopped) from whatever chocolate you used.
3 tablespoons water
2 tablespoons of vanilla or almond extract (if you want to make it chocolate mint add only 1/2 teaspoon of mint extract)
4 eggs at room temperature
Pinch of Kosher salt


If you ware not using chocolate chips, break the chocolate in small pieces.


Separate the egg yolks from the whites.
Mix the chocolate and water in a bain-marie bowl.


When the chocolate is melted remove from heat and stir until the mixture is smooth.
Let cool to near room temperature.
In a separate bowl mix the egg whites and the salt.


Beat in until the egg whites are thick, fluffy and smooth.
Mix the egg yolks into the cooled chocolate mixture, but mix it well.


Fold gently to lighten up the mixture.


Don't freak out if it looks like it isn't well mixed.
When it is cold and ready to eat it will look much different.


Chill for 3 hours before serving.
This last picture is the mousse made with Lindt from the step by step.