Combine raspberries, powdered sweetener, and water in a small saucepan. Cook over low heat for 4–6 minutes until thickened. Strain if desired and cool completely.
Preheat oven to 325°F (165°C). Line a 24-cup mini muffin pan with paper liners.
Mix almond flour, melted butter, powdered sweetener, and salt until the mixture resembles moist sand.
Divide the crust mixture among the muffin cups and press firmly into the bottoms.
Pre-bake the crusts for 5–6 minutes. Remove and cool slightly.
Beat softened cream cheese until smooth. Add powdered sweetener and sour cream and mix until combined.
Add eggs one at a time, followed by lemon juice, lemon zest, and vanilla. Mix gently until smooth.
Divide the cheesecake filling evenly among the prepared muffin cups, filling each approximately three-quarters full.
Add a small spoonful of cooled raspberry sauce to each cheesecake and gently swirl with a toothpick.
Bake for 15–18 minutes, until the edges are set and the centers retain a slight wobble.
Cool in the pan for 30–45 minutes.
Refrigerate for at least 3 hours before removing the liners and serving.