Preheat the oven to 325 degrees. Line a 9 inch springform pan with foil or parchment and coat in a light layer of non-stick spray. Set aside.

In a medium bowl, combine the graham cracker crumbs, sugar and melted butter. Stir until it looks like wet sand.

Press the crumb mixture into the bottom and up the sides of the prepared pan. Set aside.

In the bowl of a stand mixer, combine the softened cream cheese and sugar. Cream until smooth.

Add in the eggs and mix thoroughly - scraping the sides and mixing again.

Add in the flour and vanilla. Mix to combine.

Add in the sour cream (or yogurt) and mix well, again scraping the sides often and mixing thoroughly.

Add in the chocolate chips and mini marshmallows and fold gently to combine.

Pour the filling into the prepared crust.

Place springform pan on a baking sheet and place in the preheated oven. Bake for approximately 45-50 minutes or until the outside edges are set and there is a slight jiggle in the center when moved.

Remove the pan from the oven and sprinkle with the additional mini marshmallows.

Return to the oven and bake for an additional 5-10 minutes or until the marshmallows are puffy and just starting to brown.

Remove from the oven and allow to cool to room temperature.

Cover loosely and refrigerate for an additional 6-8 hours.

When ready to serve, drizzle with the remaining melted chocolate.