Preheat your oven to 375°F (190°C). In a mixing bowl, combine coarsely crushed pretzels, brown sugar, all-purpose flour, vanilla extract, and melted butter. Stir together until well mixed. Press this mixture into a greased 9×13-inch baking dish, reserving ½ cup for later. Bake the crust for 10 minutes until golden, then allow it to cool completely before adding the cream layer.

In a medium saucepan over medium heat, combine fresh blueberries, granulated sugar, lemon juice, and cornstarch. Stir continuously until the mixture thickens, which should take about 5-7 minutes. Remove from heat and let the blueberry topping cool to room temperature.

In a large mixing bowl, beat softened cream cheese using an electric mixer until smooth and creamy. Gradually mix in powdered sugar until fully incorporated. Gently fold in Cool Whip until the mixture is light and airy.

Once the crust has cooled, evenly spread the cream cheese layer on top of it. Spoon the blueberry pie filling over the cream layer, followed by the homemade blueberry topping, spreading it gently to avoid mixing. Sprinkle the reserved pretzel mixture on top for added crunch.

Cover the assembled Blueberry Pretzel Salad with plastic wrap and refrigerate for at least 4 hours, or ideally, overnight. Chill to allow layers to set beautifully.