In a 2-quart saucepan, heat the blueberries and granulated sugar over medium heat.
Use a potato masher to break down the blueberries, cooking for 8 to 10 minutes until the blueberries have reduced to a thick jam-like paste.
Remove cooked fruit from heat and cool to room temperature. Transfer the mixture to a bowl and refrigerate for faster cooling.
Beat together the softened cream cheese and butter until light and fluffy.
Add in vanilla extract and beat until combined.
Gradually beat in the powdered sugar until the frosting is thick and fluffy.
Beat in the vanilla extract and then the cooled blueberry reduction.
