1. Preheat your oven to 350 F (175 C). Line an 8×8 inch baking pan with parchment paper, leaving an overhang on the sides to easily lift the bars out later. In a medium bowl, combine the almond flour and 1/4 cup granulated sweetener for the crust. Pour in the melted butter and mix until well combined and crumbly. Press this mixture evenly into the bottom of the prepared baking pan. Bake for 10-12 minutes, or until lightly golden brown. Remove from the oven and let cool slightly while you prepare the filling.

2. In a large mixing bowl, using an electric mixer, beat the softened cream cheese until smooth and creamy, about 2-3 minutes. Make sure there are no lumps.

3. Gradually add the remaining 1/2 cup granulated sweetener to the cream cheese, beating until fully incorporated. Beat in the eggs one at a time, mixing well after each addition until just combined. Be careful not to overmix the eggs.

4. Stir in the heavy cream, lemon zest, fresh lemon juice, and vanilla extract until the mixture is smooth and evenly flavored. The mixture should be thick and pourable.

5. Pour the cream cheese filling evenly over the cooled crust in the baking pan. Gently sprinkle the fresh or frozen blueberries over the top of the cream cheese layer. You can gently press some of them down slightly if you wish, but don’t submerge them completely.

6. Return the pan to the oven and bake for 30-35 minutes, or until the edges are set and the center is mostly firm with a slight jiggle. The top might be lightly golden.

7. Remove the pan from the oven and let the bars cool completely at room temperature on a wire rack. Once cooled, transfer the pan to the refrigerator and chill for at least 2-3 hours, or preferably overnight, until thoroughly set. This chilling step is essential for firm, sliceable bars.

8. Once chilled, use the parchment paper overhang to lift the entire slab of bars out of the pan. Place on a cutting board and slice into 9 or 16 squares, depending on your desired serving size. Serve cold.