Place 6 tablespoons of butter in a 9” microwave-safe pie dish. Microwave until butter is melted. Sprinkle the graham cracker crumbs over the melted butter and stir with a fork, then press into the bottom and up the sides of the pie dish. Freeze for at least 30 minutes, or until firm.

Preheat oven to 325°F.

Beat cream cheese in a large bowl, using a hand or a stand mixer, until fluffy and smooth. Add 1/2 cup sugar, sour cream, and vanilla extract and beat until smooth. Add the eggs and mix well, until no lumps remain. (It’s important to start with room temperate ingredients to avoid a lumpy cheesecake!)

Pour cheesecake into prepared crust.

Melt remaining 2 tablespoons of butter in a small bowl. Stir in 1 teaspoon sugar and cocoa powder. Drop spoonfuls of cocoa mixture in rows across the crust, then use a toothpick or the back of a butter knife to create the tic tac toe pattern by dragging it horizontally and then vertically through the chocolate.

Bake for 30-40 minutes until the cheesecake seems solid around the edges and is just turning golden brown. The center will jiggle slightly even when it’s done. Cool completely to room temperature, then cover with plastic wrap and chill for at least 5 hours or overnight before serving.