Preheat oven to 350F. Combine butter, 1 1/2 cup almond flour, 1/4 cup erythritol, vanilla, and a pinch of salt. Press evenly into a 9x9″ parchment paper-lined baking dish. Bake for 15 minutes or until crust starts to become golden on the edges.
While the crust is baking, in a large bowl, combine the ingredients for the filling and beat or whisk until lump free and fully incorporated.
Pour the filling onto the pre-baked crust & bake for 25 minutes. Cool for at least 30 minutes, cut into 12-16 small squares and sprinkle with powdered erythritol if desired.
Reduce the sweetener by 1/4 cup or to your taste if desired.