1. Prepare the Crust

1. Preheat oven to 325°F (165°C). Grease a 9-inch springform pan or line it with parchment paper.
2. Combine almond flour, melted butter, erythritol, and vanilla extract in a bowl; mix until well blended.
3. Press the mixture into the pan’s bottom and bake for 10–12 minutes until golden and firm. Let it cool.

2. Make the Cheesecake Filling

1. Beat softened cream cheese in a large bowl until smooth.
2. Add sour cream, erythritol, vanilla extract, and lemon juice (if using), and mix until creamy.
3. Incorporate eggs one at a time, mixing thoroughly after each addition.
4. Pour the filling over the cooled crust, smoothing the top.

3. Bake

1. Bake for 50–60 minutes until the edges are set, and the center is slightly jiggly.
2. Turn off the oven, cool the cheesecake inside with the door ajar for 1 hour, then let it cool completely at room temperature.
3. Refrigerate for at least 4 hours or overnight before serving.

4. Serve

1. Carefully remove the cheesecake from the springform pan and place it on a serving plate.
2. Garnish with keto-friendly toppings like whipped cream or fresh berries, if desired.