Mix the Crust: In a medium bowl, stir together the graham cracker crumbs, unsweetened cocoa powder, and melted butter until thoroughly combined. Press this mixture into the bottom of a greased 9-inch springform pan evenly. Bake at 350°F (180°C) for 8 minutes and cool while preparing the filling.

Prepare the Filling: In your mixing bowl, beat the softened cream cheese on medium speed until smooth and creamy. Gradually add in the granulated sugar, mixing until fully combined and fluffy.

Add Remaining Ingredients: Add in the sour cream, crushed pistachios, eggs, vanilla extract, and almond extract. Mix well until everything is incorporated, ensuring a smooth consistency.

Bake the Cheesecake: Pour the cheesecake filling over the cooled crust in the springform pan. Bake at 325°F (160°C) for 55-60 minutes or until the edges are set and the center is slightly jiggly.

Cool and Chill: Remove the cheesecake from the oven and let it cool for 1 hour. Then, refrigerate for at least 4 hours or overnight for optimal texture.

Serve: Gently release the springform pan and top the cheesecake with whipped cream and additional crushed pistachios if desired. Slice and enjoy!