Preheat your oven to 325°F (163°C). In a bowl, combine graham cracker crumbs with sugar and melted butter until it resembles wet sand. Press into a greased 9-inch springform pan and bake for 8-10 minutes until slightly golden. Cool completely.

Wrap the outside of the springform pan with aluminum foil tightly to prevent water leakage during baking. Optionally, use a slow cooker liner for additional protection.

In a large mixing bowl, beat cream cheese, sugar, and vanilla until smooth. Add eggs one at a time, mixing on low. Fold in mini marshmallows and dark chocolate evenly.

Pour the filling into the cooled crust, smoothing the top. Sprinkle with remaining mini marshmallows, chocolate, and reserved graham crumbs for texture. Place in a roasting pan, fill with boiling water halfway up the cheesecake sides. Bake for 55-60 minutes until center is slightly jiggly.

Turn off the oven, let the cheesecake sit inside for 45 minutes. Then cool at room temperature for an hour before refrigerating. Chill overnight for best texture and flavor.

Release the cheesecake from the springform pan, toast mini marshmallows on top with a kitchen torch if desired, and drizzle with chocolate syrup before serving. Enjoy!