Prepare the pie crust by rolling out a pre-made or homemade dough and pressing it into a pie dish. Bake the crust according to the recipe instructions until golden brown.
In a double boiler or microwave, melt the chocolate, stirring occasionally until smooth and completely melted.
In a separate bowl, beat the eggs and sugar until light and fluffy. Slowly pour in the melted chocolate, mixing until well combined.
In another bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the chocolate mixture until fully incorporated.
Pour the chocolate mousse into the prepared pie crust and smooth the top. Refrigerate the pie for at least 2 hours, or until set.
Serve the Chocolate Mousse Pie chilled, garnished with a dusting of cocoa powder, shaved chocolate, or a dollop of whipped cream, if desired.