Place the almond flour, coconut flour, melted butter, powdered Erythritol, and salt in a mixing bowl and stir to combine.
Press the mixture into the bottom of a 7-inch, non-stick, loose-bottom baking tin and smooth with a spatula or spoon. Alternatively, use individual ramekins or a muffin tin for bite-sized cheesecakes. In this case, you are reducing the chilling time to 40 minutes.
Next, make the filling: Beat the cream cheese with the powdered Erythritol, lemon juice, and vanilla with an electric mixer until smooth.
In another bowl, whisk the cream until it doubles in volume and forms a very stiff peak. Fold in the cream cheese mixture.
Spoon the mixture on top of the base and flatten with a spatula.
Refrigerate for an hour before slicing and serve cold, optionally topped with low carb fruit.