In the bowl of a stand mixer fitted with the paddle attachment, beat cream cheese and sour cream together on medium low speed until smooth and light. Reduce speed to low and add confectioners sugar, 1/4 cup at a time, until completely smooth and combined. Stir in vanilla extract and remove bowl from stand. Fold Cool Whip into the mix until well combined. Place in a clean bowl, cover and refrigerate for 4-6 hours.
Spray two small baking sheets with nonstick cooking spray and line with parchment paper. Lightly spray parchment paper. In a large bowl, combine Rice Krispies and Fruity Pebbles; set aside.
In a large pot, melt butter, then stir in marshmallows. Cook until completely melted, then remove from heat and pour over cereal, stirring to coat while marshmallows are still hot. Pour onto one of the prepared baking sheets and press gently into an even layer. Let cool 5 minutes.
Cut the treats into 2-inch squares. Press the squares to ½-inch thick, then scoop a heaping teaspoon of the cheesecake filling into the center. Use a 1-inch ice cream scoop if available. Fold the edges of the cereal around the filling, enclosing completely. Shape the treats into a circle, then set aside on prepared baking sheet and repeat with remaining ingredients. Place the treats in the freezer for 15 minutes then serve.