Preheat your oven to 350°F (175°C). Crush graham crackers in a food processor. Mix with melted butter and chocolate chips until moist. Press into a 9-inch springform pan. Bake for 10 minutes and let cool.

In a mixing bowl, beat softened cream cheese until smooth. Gradually add sour cream and heavy cream, mixing well. Fold in chopped marshmallows.

Pour cheesecake filling over the cooled crust, spreading evenly. Tap the pan to remove air bubbles and chill in the refrigerator for at least 4 hours.

Prepare ganache by heating equal parts heavy cream and chocolate chips in a saucepan. Once the cheesecake is chilled, pour ganache over the top and arrange marshmallows for toasting.

Toast marshmallows using a kitchen torch or broiling in the oven until golden brown. Slice and serve with optional berries or ice cream.