Combine the graham cracker crumbs, melted butter, sugar, and salt in a medium bowl. Mix until the consistency resembles wet sand. The mixture should hold together when pressed between your fingers.
Divide the graham cracker mixture evenly among 8 serving glasses or jars (about 3 tablespoons per cup). Press firmly with the back of a measuring spoon to create a compact layer.
In a medium saucepan, combine blueberries, sugar, and lemon juice. Bring to a simmer over medium heat, stirring occasionally. Cook until blueberries begin to burst, about 3-4 minutes.
Add the cornstarch mixture and continue cooking for 1-2 minutes until thickened to coat the back of a spoon. Remove from heat and allow to cool completely.
In a large bowl, beat the softened cream cheese and sugar until smooth and fluffy, about 2 minutes. Add lemon juice, lemon zest, and vanilla extract. Continue beating until well incorporated.
Gently fold the whipped heavy cream into the cream cheese mixture using a rubber spatula. Use a folding motion rather than stirring to maintain the airiness.
Spoon or pipe half the cheesecake mixture over the graham cracker crusts. Add a layer of cooled blueberry sauce (reserve some for topping). Follow with remaining cheesecake mixture.
Refrigerate the cups for at least 4 hours or preferably overnight. Before serving, top with remaining blueberry sauce and fresh blueberries.