Blueberry Sauce: Heat frozen blueberries in a saucepan over medium high heat with two tablespoons of water. When the berries start to heat up & sizzle, reduce heat to medium. Cook for about 5 minutes, until berries burst and create a sauce. Stir a few times while cooking. Transfer to a container. Put sauce in the refrigerator to cool completely.
Pulse the graham crackers in the food processor until you get a fine crumb.
Take half of the yogurt and sweeten with vanilla stevia drops or your favorite natural sweetener ~ to taste. Mix into the other half a few spoonfuls of blueberry sauce.
Assemble: Layer the sauce, 2 yogurts and graham cracker crumbs in parfait glasses. Alternate layers so they look pretty. Top with fresh blueberries and graham cracker crumbs.