• Preheat the oven to 350°F. Spray a 9×13-inch baking dish with nonstick cooking spray. Set aside.

Crust

• In a large bowl, stir the flour, and sugar together. Using your hands or a pastry cutter, incorporate the butter until the crumbs have pea-sized pieces of butter.
• Press the crust mixture into the prepared baking pan. Bake for 15-18 minutes, or until the edges are barely golden.

Filling

• To a large mixing bowl, add cream cheese and sugar. Using a hand mixer, beat on medium speed until smooth and creamy (about 2 minutes).
• Add the sour cream and vanilla. Blend in until smooth and creamy, stopping to scrape down the sides of the bowl as needed.
• With the mixer on low, add in eggs, one at a time, until fully incorporated, scraping the sides and bottom of the bowl after each addition.
• Add lemon zest and lemon juice. Mix until just incorporated.
• Pour the filling over the crust. Sprinkle the blueberries evenly over the filling.

Crumble Topping

• In a medium bowl, whisk together flour and sugar. Stir in melted butter and lemon zest until a crumbly dough forms.
• Sprinkle the crumble topping evenly over the blueberries.
• Bake 50-55 minutes, or until the filling is just set and the crust is golden brown.
• Let the bars cool on counter for 30 minutes. Then place them in the refrigerator to finish chilling for about 4 hours.
• When ready to serve, make the lemon glaze.

Lemon Glaze

• In a medium bowl, whisk confectioners' sugar, milk, lemon juice, and vanilla extract until smooth. Add more milk if needed, one teaspoon at a time, to reach your desired consistency.
• Drizzle over cooled bars. Serve.