Prepare the crust by combining graham cracker crumbs and melted butter in a bowl. Press this mixture firmly into the bottom of a 9-inch springform pan.

In another bowl, beat the softened cream cheese until smooth. Gradually add sweetened condensed milk while mixing until well-combined.

Gently fold in marshmallow fluff and vanilla extract until fully incorporated.

In a separate bowl, whip heavy cream until stiff peaks form. Carefully fold this whipped cream into the cream cheese mixture to maintain airiness.

Pour the filling over the prepared crust and spread evenly. Cover and refrigerate for at least 4 hours or overnight until set.