In a large mixing bowl add the softened cream cheese, and beat with a hand mixer or in a stand mixer on high speed until smooth.
Add lemon zest and sugar and beat until smooth and well combined.
Add the eggs one at a time and beat until combined.
Add sour cream/ yogurt, lemon juice, salt, and beat for a few more minutes.
Now add all purpose flour and beat just to combine. Scrape down the sides.
Add blueberries and gently fold in the batter with a spatula.
Pour the lemon blueberry filling on the prepared crust. Add some blueberries on top and crumble the reserved crust on top with your hands or a grater.
Bake for 55-60 minutes or until a toothpick inserted in the center comes out clean. Allow the bars to cool at room temperature on a wire rack. When completely cool, chill in the refrigerator for an hour. Remove from the baking pan and cut into squares.