Preheat oven to 350oF. For the crust, combine almond flour, butter, Truvia, xanthan gum and salt. Using a hand mixer, blend until well combined and mixture resembles crumbs.
Line an 8x8 inch baking pan with parchment paper and press mixture evenly into the bottom. Bake for 10 minutes. Set aside and let cool.
Reduce oven temperature to 275oF.
For the filling, beat cream cheese in a large bowl until smooth.
Beat in Truvia, egg, cream, lemon zest and lemon juice until well combined.
Spread filling over cooled crust and bake 30 minutes, or until the filling is set and barely jiggles when shaken.
Let cool for 30 minutes, then chill for at least 2 hours.