Preheat your oven to 325°F (160°C).

In a medium bowl, combine the chocolate cookie crumbs, melted butter, and granulated sugar. Mix until it resembles wet sand. Press the mixture firmly into the bottom of a 9-inch springform pan. Bake for about 10 minutes, then allow it to cool.

In another bowl, beat the cream cheese with an electric mixer until smooth and creamy. Gradually add the sugar and mix until combined. Add the vanilla and mix in the eggs, one at a time, without over-mixing.

Pour half of the cream cheese mixture into the crust. Gently fold in the melted semi-sweet and milk chocolate into the remaining cream cheese batter, then pour it over the first layer.

Place the cheesecake in the oven and bake for 50-60 minutes. It should be set around the edges but still slightly jiggly in the center. Turn off the oven and let the cheesecake cool in the oven with the door cracked open for about an hour.

While the cheesecake cools, heat the heavy cream in a saucepan over medium heat until it just begins to simmer. Remove from heat and pour over the chopped dark chocolate. Stir until smooth.

Once the cheesecake is completely cool, pour the ganache over the top, spreading it evenly. Decorate with chocolate shavings. Chill in the fridge for at least 4 hours, or overnight, for best results.