Prepare the Crust: Preheat your oven to 325°F (163°C). In a bowl, combine almond flour, melted butter, erythritol, vanilla extract, and salt. Press the mixture into the bottom of a greased 9-inch springform pan, forming an even layer. Bake for 10 minutes, then remove from oven and set aside to cool.
Make the Filling: In a large mixing bowl, beat the softened cream cheese until smooth. Add sour cream, erythritol, and vanilla extract. Mix well until combined. Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next. Stir in the lemon zest.
Assemble the Cheesecake: Pour the filling over the cooled almond crust, smoothing out the top with a spatula.
Bake: Return the pan to the oven and bake for 35 minutes, or until the edges are set but the center still jiggles slightly when shaken.
Cool: Turn off the oven, slightly open the door, and allow the cheesecake to cool inside for 1 hour to prevent cracking.
Chill: Remove the cheesecake from the oven, run a knife around the edge, and let it reach room temperature. Then refrigerate for at least 4 hours, or overnight, to set completely.
Serve: Once chilled, release the cheesecake from the springform pan, slice, and serve.