• Preheat oven to 350°F. Line a 9×9-inch baking dish with parchment paper, leaving some overhang on the sides for easy removal after baking.

Crust

• In a medium bowl, combine graham cracker crumbs, melted butter, and granulated sugar. Mix until the texture resembles wet sand.
• Press the mixture firmly into the prepared baking dish to form the crust. Set aside.

Filling

• In a large bowl, using a hand mixer, beat the cream cheese, eggs, granulated sugar, vanilla extract, and kosher salt until smooth and creamy.
• Spread the cream cheese mixture evenly over the crust.
• Scatter the blackberries evenly over the cream cheese layer and gently press them into the filling so they settle slightly.

Crumble Topping

• In a medium bowl, whisk together all-purpose flour, light brown sugar, and kosher salt. Stir in melted butter until a crumbly mixture forms.
• Sprinkle the crumble topping evenly over the blackberry layer.
• Bake for 35 to 40 minutes, or until the center is set and the crumble topping is lightly golden brown.
• Transfer the baking dish to a wire rack and let the bars cool completely at room temperature, about 1 hour.
• Once cooled, transfer the dish to the refrigerator and chill for at least 1 hour before slicing and serving.