Fluffy Whipped Blueberry Butter

In a medium saucepan over medium heat, combine blueberries, water, and sugar. Stir regularly, bringing the mixture to a low boil. In a small bowl or mug, mix together the cornstarch and water until a smooth slurry is formed. Slowly stir slurry into blueberries. Simmer blueberries until sauce is thickened enough to coat the back of a spoon. This should take 5 to 10 minutes. Remove from heat and stir in vanilla. Let cool completely before adding to whipped blueberry butter portion of the recipe. These quantities will give you more blueberry sauce than needed for the butter, about 2-1/4 cups total. Enjoy the remaining sauce spooned over pancakes, waffles, and ice cream.