Combine graham cracker crumbs, sugar, cinnamon and butter in a bowl. Press onto the bottom of an ungreased 9-inch pan and refrigerate for 30 minutes.

Preheat oven to 300 degrees F (150 degrees C).

Place blueberries and cornstarch into a blender and blend to a puree until smooth. Pour blueberry sauce into a saucepan.

Bring to a boil over high heat. Boil and stir until sauce is thick and shiny, about 2-4 minutes. Set aside 1/3 cup blueberry sauce; let it cool. Cover and refrigerate remaining sauce for serving.

Beat cream cheese in a mixing bowl with an electric mixer until light and fluffy; slowly beat in condensed milk. Mix in lemon juice and vanilla extract, then beat in eggs on low speed until just combined. Pour half of cream cheese mixture over crust; drop half of reserved blueberry sauce by 1/2 teaspoonfuls on cream cheese layer. Carefully spoon remaining cream cheese mixture over sauce; drop remaining blueberry sauce by 1/2 teaspoonfuls on top. Cut through top layer only with a knife to swirl blueberry sauce.

Bake in preheated oven until center is almost set, 50-60 minutes. Cool on a wire rack for 10 minutes. Use a knife around edge of pan to loosen and let it cool 1 hour longer. Refrigerate the blueberry cheesecake overnight. Serve reserved blueberry sauce with cheesecake.