In a mixing bowl, combine the crushed chocolate graham crackers, granulated sugar, and melted unsalted butter. Mix until well combined and press into the bottom of a greased 9x9-inch baking pan. Bake at 350°F (175°C) for about 8-10 minutes, then set aside to cool.
Melt the unsweetened baking chocolate using a double boiler or microwave, stirring until fully melted. Allow to cool slightly.
In a large mixing bowl, beat the softened salted butter until creamy. Gradually add the powdered sugar and beat until light and fluffy. Mix in the vanilla extract and melted chocolate until fully incorporated.
Add the eggs, one at a time, beating well after each addition. Continue mixing for about 5 minutes until the filling is thick and fluffy.
Pour the chocolate filling over the cooled graham cracker crust, smoothing the top with a spatula. Refrigerate for at least 4 hours, or until set.
Once set, cut into squares and serve with fresh whipped cream and chocolate shavings.