Preheat your oven to 325°F (160°C).

In a mixing bowl, combine chocolate wafer crumbs, melted butter, and sugar, and mix well. Press the mixture into the bottom of a 9-inch springform pan to form the crust. Bake for 10 minutes, then remove from the oven and let cool.

In another mixing bowl, beat the softened cream cheese until smooth. Gradually add sugar and continue to beat until well combined.

Add the sour cream, eggs, and vanilla extract to the cream cheese mixture, mixing until just combined. Do not overbeat.

Divide the mixture in half. To one half, add the melted semi-sweet chocolate chips, and to the other half, add the melted white chocolate chips. Mix until combined.

Pour the semi-sweet chocolate mixture over the cooled crust, spreading evenly. Then pour the white chocolate mixture on top, spreading gently to avoid mixing.

Bake in the preheated oven for 50-60 minutes, or until the center is set but still slightly jiggly. Turn off the oven and leave the cheesecake inside for an additional hour.

Remove from the oven and allow to cool at room temperature. Once cooled, refrigerate for at least 4 hours (preferably overnight) until fully chilled.

For the ganache, heat the heavy cream in a double boiler or microwave until just boiling. Remove from heat and add chopped semi-sweet chocolate, stirring until smooth.

Once the cheesecake is chilled, pour the ganache over the top, spreading it evenly. Refrigerate again for at least 30 minutes to set the ganache.

Carefully remove the cheesecake from the springform pan and slice it into 12 pieces.