In a medium saucepan, combine the fresh blueberries, granulated sugar, brown sugar, and water over medium heat. Crush some blueberries gently as it warms. Bring to a boil, then whisk in cornstarch mixture until thickened. Stir in lemon zest and juice, then chill until cool.

Preheat your oven to 325°F (160°C). Blend melted butter, all-purpose flour, and chopped pecans in a mixing bowl. Press into an 8x8-inch baking dish. Bake for 15 minutes or until golden. Cool completely.

Whip heavy whipping cream and vanilla in a bowl until soft peaks form. Beat cream cheese and powdered sugar in a separate bowl until smooth. Fold whipped cream into cream cheese mixture until just combined.

Spread creamy filling over cooled pecan crust. Spoon chilled blueberry mixture over filling. Cover and refrigerate for at least 4 hours or overnight.

Slice into squares and serve chilled, garnished with fresh blueberries or whipped cream.