Make the crust: Combine almond flour, melted butter and erythritol until thoroughly blended. Press the crust down securely in the bottom of a greased springform pan and bake at 325°F (160°C) for 10 minutes.
Make the filling: In a large mixing bowl, beat softened cream cheese and erythritol until smooth. Beat in eggs, one at a time, just until combined. Add vanilla extract and sour cream, mixing well. Pour over the crust.
Bake the cheesecake: Slide the pan in the oven and bake for 45–50 minutes. They should be set around the edges and the center should be slightly jiggly. Set it aside to cool completely in the pan
Make the topping: In a small pot, cook blueberries, lemon juice, erythritol and water until thick and shiny.
Set & chill: Add the blueberry topping to the top of cooled cheesecake and refrigerate 4 hours or until cold before slicing.
