Step 1: Prepare the Crust

1. Preheat your oven to 350°F (175°C).
2. In a bowl, mix the chocolate cookie crumbs and melted butter until evenly combined.
3. Press the mixture firmly into the bottom of a 9-inch springform pan.
4. Bake the crust for 10 minutes, then set aside to cool.

Step 2: Make the Cheesecake Filling

1. In a large bowl, beat the cream cheese and sugar until smooth and creamy.
2. Add the eggs one at a time, beating well after each addition.
3. Mix in the vanilla extract and sour cream until fully incorporated.

Step 3: Create the Swirls

1. Divide the batter evenly into three bowls.
2. Add a few drops of purple food coloring to one bowl, green to the second, and black to the third. Mix each until the colors are vibrant.
3. Pour the batter into the prepared crust in alternating dollops of each color, layering them randomly to create a marbled effect.
4. Use a toothpick or butter knife to gently swirl the colors together for a magical, witchy design.

Step 4: Bake the Cheesecake

1. Reduce the oven temperature to 325°F (160°C).
2. Place the cheesecake in the oven and bake for 50-60 minutes, or until the edges are set but the center still jiggles slightly.
3. Turn off the oven, crack the door open slightly, and let the cheesecake cool inside for 1 hour.

Step 5: Chill and Decorate

1. Remove the cheesecake from the oven and refrigerate for at least 4 hours or overnight to fully set.
2. Before serving, top with whipped cream, sprinkles, or edible glitter for a festive touch.