In a medium saucepan, combine blueberries, sugar, vanilla extract, and lemon juice. Mix water and corn starch until smooth and add to the saucepan. Heat over medium heat until simmering, then reduce and cook for 2-3 minutes.

Preheat your oven to 350°F (175°C) and line muffin cups with paper liners. In a bowl, mix graham cracker crumbs and sugar. Add melted butter and mix until it resembles wet sand. Press into the muffin cups and bake for 8 minutes. Allow to cool completely.

Lower the oven temperature to 325°F (160°C). Beat softened cream cheese with sugar until creamy, about 5 minutes. Add vanilla, lemon juice, and lemon zest; beat for another minute. Incorporate eggs one at a time, then fold in sour cream until combined.

Spoon cheesecake filling into muffin cups on top of the cooled crust. Add blueberry mixture on top and swirl with a toothpick.

Bake for 18-20 minutes until centers are slightly jiggly but set. Cool at room temperature for 30 minutes, then refrigerate for at least 3 hours before serving.