Heat the oven to 350°F. Line the bottom and sides of an 8x8-inch square metal baking pan with 2 sheets of parchment paper.

Break 16 graham cracker sheets into rough pieces and place in a food processor. Add 1/4 cup granulated sugar and 1/4 teaspoon kosher salt. Process until the texture is like sand.

Add 9 tablespoons melted unsalted butter and pulse to combine. Reserve 2/3 cup of the mixture for topping.

Transfer the remaining mixture to the baking pan and press into an even layer.

Bake the crust for 12 to 15 minutes until fragrant and starting to darken. Let it cool slightly.

Clean the food processor. Add 16 ounces cream cheese and process until smooth and fluffy.

Add 1/2 cup granulated sugar, 2 teaspoons lemon zest, 3 tablespoons lemon juice, 1 teaspoon vanilla extract, and 1/4 teaspoon kosher salt. Process until combined.

With the motor running, add 2 large eggs one at a time and process until just incorporated.

Gently stir in 1 1/2 cups blueberries. Transfer the filling to the crust and spread evenly. Scatter the remaining 1/2 cup blueberries on top and sprinkle with reserved crumb mixture.

Bake for 30 to 35 minutes until the edges are set and the center is slightly jiggly. Let cool completely for about 2 hours.

Cover and refrigerate until chilled for at least 3 hours or overnight.

Lift the bars out using the parchment and dust with powdered sugar before serving.