Prep the pan: Preheat oven to 325°F (163°C). Grease a 9-inch springform pan and line the bottom with parchment for easy release.

Make the crust: In a bowl, combine almond flour, granular sweetener, and salt. Stir in melted butter, vanilla, and optional lemon zest. The mixture should feel like damp sand.

Press and par-bake: Press the crust evenly into the pan, going slightly up the sides. Bake for 10–12 minutes until lightly golden. Set aside to cool slightly.

Drain the ricotta: If your ricotta looks wet, spoon it into a sieve lined with paper towels or cheesecloth. Let it drain for 10–15 minutes to avoid a watery filling.

Blend the cheeses: In a large bowl, beat the softened cream cheese until smooth, 1–2 minutes. Add the drained ricotta and beat until well combined and creamy. Avoid overbeating to keep the texture light.

Sweeten and flavor: Add the powdered sweetener, salt, lemon zest, lemon juice, vanilla, and sour cream. Mix on low speed just until smooth.

Add the eggs: Beat in eggs one at a time on low speed, scraping the bowl as needed. Mix only until just combined. Overmixing can introduce air and create cracks.

Fill the pan: Pour the filling over the cooled crust. Tap the pan gently on the counter to release air bubbles. Run a knife through the batter in a few swirls to burst any remaining bubbles.

Bake low and slow: Bake at 325°F for 45–60 minutes. The edges should be set and the center slightly wobbly, like Jell-O. If the top browns too quickly, tent with foil.

Cool gradually: Turn off the oven, crack the door, and let the cheesecake sit inside for 30 minutes. This gentle cooling helps prevent cracks.

Chill to set: Remove, run a knife around the edge, and cool to room temperature. Cover and chill at least 6 hours, preferably overnight, before slicing.

Serve: Slice with a warm, clean knife. Add whipped cream, extra zest, or a few berries if you like.