Preheat your oven to 325F and line an 8×8 square with parchment paper.
In a medium bowl, prepare the crust by adding all ingredients and working them together with your hands. Once combined, add to parchment-lined pan and spread to edges.
Bake until lightly golden brown, about 20 minutes.
In the meantime, make the filling. Remove the peel from about 2 lemons and blend in a blender or with a handheld immersion blender to make a paste.
Add the paste, zest, juice, whole eggs, egg yolks, Swerve and flour to a bowl and whisk until smooth.
When the crust is finished, reduce the oven to 300F. Carefully pour the filling over the crust. Bake until the filling is just barely set, about 20 minutes.
Let the pan cool and then transfer to fridge to cool for at least 3 hours.
Slice into squares and dust with powdered Swerve.