Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and line an 8x8 inch baking dish with parchment paper.
Prepare the Crust: In a mixing bowl, combine 1 1/2 cups of flour, 1/2 cup of granulated sugar, and 1/2 cup of melted butter. Press the mixture into the bottom of the prepared baking dish to form an even crust. Bake for 10-12 minutes, or until lightly golden.
Make the Crumble Topping: In a separate bowl, combine 1/2 cup of flour, brown sugar, 1/4 cup of granulated sugar, and cinnamon. Use your fingers or a pastry blender to mix in the cold, cubed butter until the mixture forms coarse crumbs. Set aside.
Make the Cream Cheese Filling: In another bowl, beat the softened cream cheese, powdered sugar, and vanilla extract until smooth and creamy. Stir in lemon juice and gently fold in the blueberries.
Assemble and Bake: Pour the cream cheese mixture over the partially baked crust and spread it evenly. Sprinkle the crumble topping evenly over the cream cheese layer. Bake in the preheated oven for 25-30 minutes, or until the edges are set and the center slightly jiggles.
Cool and Serve: Let the bars cool completely in the pan. Once cool, lift them out using the parchment paper, slice into squares, and serve chilled.