Prepare the crust (if using): In a bowl, mix almond flour with melted butter (or coconut oil) until crumbly but pressable. Press this mixture evenly into the bottom of an 8- or 9-inch springform pan (or similar pan). Set aside.

Preheat your oven to 350°F (about 175°C) — if you plan to bake. Meanwhile, bring the softened cream cheese to room temperature so it blends smoothly.

Make the filling: In a mixing bowl (or using a mixer), beat together the cream cheese, yogurt, powdered sweetener, vanilla extract — and lemon juice if using — until completely smooth and creamy. Avoid overmixing.

Pour the filling: Spread the cheesecake filling evenly over the prepared crust (or, if skipping the crust, just pour into a parchment-lined pan).

Bake (if using crust): Place the cheesecake on the middle oven rack. Bake about 30 minutes (or until the edges are set but the center may still have a slight wobble). After baking, turn off the oven and leave the cheesecake inside with the door cracked for a few minutes, then remove and let cool.

Chill: Once cooled to room temperature, refrigerate the cheesecake overnight (or at least several hours) so it firms up properly before slicing.