Prep your tools: Line a mini muffin tin with paper liners or set out a silicone candy mold. If using the crust, mix almond flour, melted butter, and sweetener in a small bowl until it resembles damp sand.
Press 1/2 teaspoon into each cavity and set aside.
Beat the base: In a mixing bowl, blend softened cream cheese and butter with a hand mixer until completely smooth, fluffy, and lump-free, about 2–3 minutes.
Add sweetness and flavor: Beat in the powdered sweetener, lemon zest, lemon juice, vanilla (if using), and a pinch of salt. Start with 2 tablespoons of lemon juice, then taste and add the third tablespoon if you want it tangier.
Adjust the texture: Add heavy cream 1 tablespoon at a time and beat until the mixture is thick, creamy, and pipeable. It should hold soft peaks but not feel stiff.
Taste and fine-tune: Sweeteners vary.
Add another teaspoon or two of powdered sweetener for more sweetness, or more zest for extra zing. Balance with a tiny pinch of salt if needed.
Fill the molds: Spoon or pipe the mixture into your prepared molds or mini muffin liners, about 1–1.5 tablespoons per cavity, on top of the optional crust if using. Smooth the tops with a spoon.
Chill to set: Refrigerate for 1–2 hours until firm.
For a faster set, freeze for 25–35 minutes. They should pop out cleanly once chilled.
Finish and serve: Optional: Dust lightly with extra lemon zest before serving for color and aroma.