01 - Preheat oven to 325°F. Line the bottom of a 9-inch springform pan with parchment paper and lightly grease the sides.
02 - In a mixing bowl, combine almond flour, erythritol, melted butter, cinnamon, and salt until a crumbly dough forms. Press the mixture firmly and evenly into the bottom of the prepared pan. Bake for 10 minutes, then remove and allow to cool completely.
03 - In a small saucepan, combine chopped rhubarb, erythritol, lemon juice, and water. Cook over medium heat, stirring frequently, until the rhubarb breaks down and the mixture reaches a jam-like consistency, about 8 minutes. Remove from heat and set aside to cool.
04 - Using an electric mixer, beat softened cream cheese and erythritol on medium speed until completely smooth and free of lumps. Add sour cream and blend well. Incorporate eggs one at a time, mixing just until each is combined. Stir in vanilla extract and lemon zest. Avoid overmixing to prevent air pockets.
05 - Pour the cheesecake filling over the cooled crust, spreading evenly. Spoon small dollops of the cooled rhubarb compote across the surface. Using a butter knife or skewer, gently drag through the compote dollops to create decorative swirls throughout the batter.
06 - Tap the springform pan firmly on the counter to release trapped air bubbles. Place in the preheated oven and bake for 45–50 minutes, until the edges are set and the center maintains a slight jiggle. Turn off the oven, crack the door open, and let the cheesecake rest inside for 1 hour to cool gradually.
07 - Remove the cheesecake from the oven and transfer to the refrigerator. Chill for at least 2 hours or until fully set before slicing and serving.