Heat the cream until boiling. Lower the heat and add the Mexican chocolate. Stir over low heat until it melts. Add the rest of the chocolate and allow it to melt, stirring constantly until all chocolate is melted and mixture is very smooth. Set aside to cool to room temperature.
Over medium-high heat, met the butter--in fact brown it just a little until it releases a nutty aroma, then set aside to cool slightly. Slightly crush the crackers and put them in a food processor with the almonds. Grind to form a coarse meal. Transfer the meal to a bowl and toss it with butter. Lightly press the mixture into a 10-inch pie plate. Set aside.
Whip the chilled cream until stiff, then fold it into the room temperature chocolate filling mixture. Fold thoroughly, until no more white streaks appear, then mound the chocolate mix into the pie shell.
Refrigerate 2 hours, preferably overnight, and serve.
Here is another Mexican Chocolate Pie recipe that uses pudding mix for the filling.