Make the filling. Combine the heavy cream and chocolate in a small saucepan or in a microwave-safe bowl. Heat, stirring frequently, until the chips melt and the mixture is smooth. If doing this in the microwave, heat for 30 seconds at 50% power, stirring in between. ½ cup (120 ml) heavy cream 12 ounces (340 g) semi-sweet chocolate
Beat cream cheese and sugar. In a large mixing bowl (I like to use my stand mixer with my paddle attachment) beat together the cream cheese and sugar at low speed, until thoroughly combined. Scrape the bottom and sides of the bowl with a spatula and beat until smooth. You don’t want to continue to mix the cream cheese at this point or it will incorporate too much air and cause your cheesecake to crack so mix briefly. 3 8- ounce packages full-fat cream cheese 1 cup (200 g) granulated sugar
Add eggs. Add the eggs one at a time, beating to combine. Scrape down the bowl as needed. 4 large eggs
Add vanilla and cocoa. Stir in the vanilla, then the cocoa powder. 1 ½ teaspoons vanilla extract 2 Tablespoons unsweetened or Dutch cocoa powder
Add melted chocolate mixture. Add the chocolate/cream mixture, beating on low speed until thoroughly combined. Scrape the bottom and sides of the bowl with a spatula; and beat to combine briefly, just until smooth.
Add batter into the crust. Spread batter on top of cookie crust. Mixture will be thick. Smooth into an even layer. Place the pan on a baking sheet. Bake the cake (at 350℉) for 45 to 50 minutes, until a toothpick inserted into the cake comes out clean and the internal temperature (if testing with a thermometer reads 175oF). Insert a toothpick, about an inch from the edge, not directly in the middle. The center may not look set quite yet but will continue to bake up as it cools.
Cool the cheesecake. Turn off the oven, crack the oven door open several inches, and allow the cheesecake to cool in the oven for 1 hour. Remove the cheesecake from the oven. Cover the cheesecake and refrigerate for up to 4 hours until firm or overnight.