Prep the pan. Line a 9-inch springform pan with parchment on the bottom. Lightly grease the sides.
Preheat your oven to 325°F (163°C).
Make the crust. Stir together 2 cups almond flour, 1/4 cup granulated sweetener, 1 teaspoon cinnamon, a pinch of salt, 1 teaspoon vanilla, and 6 tablespoons melted butter until it looks like damp sand.
Par-bake the crust. Press the mixture firmly into the pan. Bake for 10 minutes, then cool while you make the filling.
Beat the cream cheese. In a large bowl, beat 24 ounces of cream cheese until smooth and fluffy. Scrape the bowl so no lumps remain.
Add sweetener and sour cream. Mix in 3/4 cup powdered or granulated keto sweetener, 1 cup sour cream, 2 teaspoons vanilla, and a pinch of salt.
Blend until silky.
Add eggs and cream. Beat in 3 large eggs, one at a time, on low speed. Finish with 1/4 cup heavy cream. Mix just until combined—don’t overbeat.
Make the cinnamon swirl. In a small bowl, stir 1/3 cup melted butter, 1/2 cup brown-style keto sweetener, 1–1.5 tablespoons cinnamon, 1/2 teaspoon vanilla, and 1–2 tablespoons almond flour (optional, to thicken).
You want a drizzly paste.
Layer and swirl. Pour half the cheesecake batter over the crust. Drizzle half the cinnamon mix in zigzags. Add the remaining batter and drizzle the rest.
Use a thin knife or skewer to lightly swirl—don’t overdo it.
Bake low and slow. Place the pan on a baking sheet. Bake at 325°F for 45–60 minutes. The edges should be set and the center slightly jiggly like Jell-O.
If browning too fast, tent with foil.
Cool gently. Turn the oven off, crack the door, and let it rest inside for 30 minutes. Then remove and cool on a rack to room temperature.
Chill to set. Cover and refrigerate at least 6 hours, preferably overnight. This step is crucial for texture and clean slices.
Optional glaze. Beat 2 ounces cream cheese, 1/3 cup powdered sweetener, 1–3 tablespoons cream or almond milk, 1/2 teaspoon vanilla, and a pinch of cinnamon until pourable.
Drizzle over the chilled cheesecake before serving.
Slice smart. Warm a sharp knife under hot water, wipe dry, and slice. Clean the knife between cuts for neat layers.