01 - Preheat oven to 350°F. Grease a 9x9-inch baking dish lightly with butter or cooking spray.
02 - Combine flour, melted butter, pecans, sugar, and salt in a medium bowl. Mix until crumbly and evenly moistened. Press mixture firmly into the bottom of the prepared baking dish.
03 - Bake for 18-20 minutes until edges are lightly golden. Remove from oven and let cool completely in the dish.
04 - Beat softened cream cheese and powdered sugar in a large bowl until smooth and creamy, about 2 minutes. Add vanilla extract and mix until combined.
05 - In a separate chilled bowl, whip cold heavy cream with electric mixer until stiff peaks form, about 3-4 minutes.
06 - Gently fold whipped cream into the cream cheese mixture using a rubber spatula until no white streaks remain. Do not overmix.
07 - Spread the cream cheese filling evenly over the completely cooled crust using an offset spatula.
08 - Combine blueberries, sugar, cornstarch, lemon juice, water, and lemon zest in a medium saucepan. Cook over medium heat, stirring constantly, until mixture thickens and becomes glossy, about 6-8 minutes.
09 - Remove saucepan from heat and let blueberry mixture cool to room temperature, about 20-30 minutes, stirring occasionally.
10 - Carefully spread the cooled blueberry topping evenly over the cream cheese layer.
11 - Cover dish with plastic wrap and refrigerate for at least 1 hour, or up to overnight, before serving. Cut into squares and serve cold.