Coarsely chop the mint leaves, and combine them with the heavy cream in a small saucepan. Bring the cream to a simmer over medium-high heat, and just before it boils, remove the pan from the heat.
Cover the pan with a tight-fitting lid and let it sit at room temperature for about an hour to infuse the cream with mint flavor. After an hour, pour the cream through a strainer into a bowl and squeeze the mint leaves tightly to remove any excess cream.
Refrigerate the cream until cold. Refrigerate a mixing bowl and a whisk attachment as well. Once the cream is cold, whip it in the chilled bowl until it forms peaks. Refrigerate the whipped cream while you prepare the rest of the recipe.
Combine the sugar, cream cheese, and 3/4 cup butter in a bowl. Beat at medium speed, scraping the bowl often, until well mixed. Add chocolate, continue beating until well mixed. Add egg substitute; continue beating, scraping bowl often, until light and fluffy. Fold in half of mint whipped cream.
Spoon into cooled pie shell, top with remaining whipped cream, garnish with mint leaves and shaved chocolate mint.