Bring cream cheese, eggs, and sour cream to room temperature for 1-2 hours before starting.
Preheat oven to 325°F. Line the bottom of a 9-inch springform pan with parchment paper, grease sides, and wrap the outside tightly with heavy-duty foil.
Combine almond flour, monk fruit sweetener, and cinnamon. Stir in melted butter until mixture resembles wet sand.
Press crust firmly into the prepared pan. Bake for 10-12 minutes until edges are golden. Set aside to cool.
Beat softened cream cheese on medium speed for 2 minutes until smooth. Add monk fruit sweetener and mix until combined.
Mix in lemon juice, vanilla extract, and salt on low speed until just combined.
Add eggs one at a time, mixing on low after each addition until yolk disappears. Add sour cream and heavy cream, mixing until smooth.
Pour filling over the pre-baked crust and smooth the top. Place the springform pan inside a roasting pan and fill with hot water to 1 inch up the sides.
Bake for 55-65 minutes until edges are set but the center still wobbles gently.
Turn off the oven and leave the cheesecake inside with the door slightly ajar for 1 hour. Remove from oven and cool at room temperature for another hour.
Cover and refrigerate for a minimum of 6 hours, but ideally overnight.
Run a knife around the edge of the pan, release the springform, and serve chilled with optional toppings.