In a large pot, melt butter over medium heat. Add mini marshmallows and stir until completely melted. Remove from heat.
Stir in Rice Krispies cereal until well coated. Press the mixture into the bottom of a greased 9-inch springform pan to form the crust.
In a mixing bowl, combine softened cream cheese, granulated sugar, and vanilla extract. Beat with an electric mixer until smooth.
Fold in whipped cream and melted white chocolate chips until the mixture is uniform.
Pour the cream cheese mixture over the crust in the springform pan. Smooth the top with a spatula.
Refrigerate for at least 4 hours, or until set.