01 - Preheat oven to 325°F. Lightly grease a 9-inch springform pan and line the bottom with parchment paper.
02 - In a medium bowl, combine almond flour, powdered erythritol, melted butter, cinnamon, and salt until the mixture resembles damp sand. Press the mixture evenly into the bottom of the prepared pan. Bake for 10 to 12 minutes until just golden. Remove from the oven and let cool completely.
03 - While the crust cools, combine chopped rhubarb, water, and powdered erythritol in a small saucepan. Bring to a simmer over medium heat and cook for 8 to 10 minutes, stirring occasionally, until the rhubarb softens and the mixture thickens. Remove from heat, stir in vanilla extract, and set aside to cool.
04 - In a large bowl, beat softened cream cheese and powdered erythritol with a hand or stand mixer until completely smooth. Add the eggs one at a time, mixing thoroughly after each addition. Blend in sour cream, vanilla extract, lemon zest, and heavy cream until fully incorporated and creamy.
05 - Pour the cheesecake filling over the cooled crust, spreading evenly. Drop spoonfuls of the cooled rhubarb compote across the surface of the batter. Use a knife or skewer to gently drag through the compote, creating a marbled swirl pattern throughout the filling.
06 - Bake for 40 to 45 minutes, or until the edges are firmly set and the center has a slight jiggle. Turn off the oven, crack the door open, and let the cheesecake remain inside for 1 hour to cool gradually and prevent cracking.
07 - Transfer the cheesecake from the oven and allow it to reach room temperature. Refrigerate for at least 2 hours before slicing into 12 portions and serving.