Preheat your oven to 325°F (163°C). Grease a 9-inch springform pan and wrap the outside with aluminum foil.

In a medium bowl, combine chocolate wafer crumbs with melted unsalted butter and press into the bottom of the prepared pan. Bake for 10 minutes and let cool.

Melt bittersweet chocolate in a double boiler until smooth, then cool slightly.

Blend full-fat cream cheese in a food processor until silky, adding granulated sugar, light brown sugar, and cocoa powder. Mix until fully combined.

Add large eggs, egg yolks, and heavy cream, mixing until just combined.

Fold in cooled melted chocolate and vanilla extract into the cream cheese mixture. Pour over cooled crust.

Place the springform pan in a larger pan filled with hot water halfway up the sides.

Bake for 1 hour and 10 minutes until edges are set and center has a slight jiggle. Cool on a wire rack for at least 1 hour.

Refrigerate for at least 6 hours or overnight before serving.

Heat heavy cream for ganache until simmering, pour over chopped semi-sweet chocolate, and whisk until smooth.

Pour ganache over chilled cheesecake and let set at room temperature for about 1 hour before slicing.