In a medium bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Mix until well combined.
Press the mixture firmly into the bottom of a 9-inch springform pan to form the crust.
In a large mixing bowl, beat the softened cream cheese, powdered sugar, and vanilla extract until smooth and creamy.
Add the marshmallow fluff to the cream cheese mixture and mix until fully incorporated.
In a separate bowl, whip the heavy cream until stiff peaks form.
Gently fold the whipped cream into the marshmallow cream cheese mixture until well combined.
Pour the filling over the prepared crust in the springform pan. Smooth the top with a spatula.
Refrigerate for at least 4 hours or until set. For best results, chill overnight.
Slice and serve chilled.