Roll out the dough: Take your pie dough out of the fridge and let it sit on the counter for a few minutes to soften slightly for easy rolling. On a floured surface, roll the dough out into a 12-inch circle. Place the dough gently into a 9x1.5-inch pie pan; you can do this by flouring a rolling pan and rolling the dough loosely around it, then unrolling it into the pan. Brush away any excess flour on the surface. With a sharp knife, trim the edges of the pastry to fit the pie pan and crimp the edges to form a border. Place the pie shell in the refrigerator for 10 minutes.

Blind bake the pie crust: Line the pie shell with a piece of parchment paper and fill with pie weights, dried beans, or uncooked rice. Place it in a 375°F/190°C oven for 15 minutes. Once the edges start to brown slightly, remove the parchment paper and pie weights. Then, use a fork to poke holes in the bottom of the pie to prevent it from puffing up. Return the crust to the oven to finish baking for another 10 minutes until it is browned and the middle of the crust feels dry. Remove from the oven and allow to cool completely.

For the chocolate mousse filling: Place the eggs and sugar in a heat-proof bowl over a double boiler on the stove top. With the heat on medium, allow the eggs to cook and the sugar to melt, whisking every minute or so to keep the eggs from scrambling. Once the sugar is completely melted, remove the stove top and whisk in melted and cooled bittersweet or semi-sweet chocolate. Set aside to continue to cool - it can be a little warmer than room temperature, but no warmer (you can place it in the fridge for a few minutes to speed up the process).

In a seperate medium bowl using an electric mixer fitted with the whisk attachment, whisk heavy cream until soft peaks form; they should hold their shape but have a soft texture. Using a spatula, gently fold 1 cup of the whipped cream into the chocolate mixture, then fold in another cup.