Preheat Oven: Preheat your oven to 350°F (175°C). Line an 8×8-inch baking pan with aluminum foil to make it easier to remove the bars after baking.
Prepare the Crust: In a medium bowl, combine the melted butter, almond flour, and confectioners sweetener. Mix until well combined, then press the mixture evenly into the bottom of the prepared baking pan. Pre-bake the crust for 7 minutes, or until set and very lightly browned. Allow the crust to cool completely before adding the next layer.
Make the Cheesecake Layer: While the crust cools, combine all the ingredients for the lemon cheesecake layer in a blender or stand mixer. Blend until the mixture is completely smooth. Once the crust has cooled, spread the cheesecake layer evenly over the crust.
Prepare the Lemon Bar Layer: In a blender or mixer, combine all the ingredients for the lemon bar layer and blend until smooth. Let the mixture chill for 10 minutes.
Assemble and Bake: Pour the lemon bar mixture evenly over the cheesecake layer. Bake in the preheated oven for 20-25 minutes, or until the top is set.
Cool and Serve: Allow the bars to cool completely before removing them from the pan. Once cooled, slice into squares and serve.