Prepare the crust: Start by crushing the graham crackers into fine crumbs, then mix with melted butter and sugar. Press this mixture firmly into the bottom of a springform pan, and bake at 350°F for about 10 minutes until golden brown.

Make the filling: In a large bowl, beat together the softened cream cheese, sour cream, and heavy cream until smooth and creamy. This should take about 3-4 minutes of mixing. Gently fold in the chopped marshmallows for an extra gooey texture.

Combine and set: Pour the cheesecake filling into the prepared crust and smooth the top. Bake at 325°F for 50-60 minutes, or until the center is set but slightly jiggly. Once done, remove from the oven and let it cool completely.

Add ganache: Once the cheesecake has cooled, prepare your chocolate ganache by heating the chocolate until melted, then pouring it over the top of the cheesecake. Allow it to set for about 15 minutes.

Top with marshmallows: Evenly distribute the additional marshmallows over the ganache. Be sure to space them out to allow for expansion during the toasting process.

Toast the marshmallows: Using a kitchen torch or the broiler, toast the marshmallows until golden brown. Keep a close eye to prevent burning, it only takes a minute or two!