These silky lemon posset cups are a dreamy chilled dessert that feels fancy but is surprisingly simple. Low carb and keto friendly, they are perfect for any occasion.
In a medium saucepan, combine the heavy cream and powdered erythritol. Bring to a gentle boil over medium heat, stirring often to dissolve the sweetener.
Once boiling, reduce the heat to medium-low and let it simmer for about 3 minutes, stirring occasionally. The cream should reduce just slightly and thicken a touch.
Remove the saucepan from the heat. Stir in the fresh lemon juice, lemon zest, and vanilla extract. Whisk gently until everything is combined. The mixture will begin to thicken noticeably as the acid reacts with the cream.
Pour the mixture evenly into 4 small ramekins or cups. Let them cool on the counter for about 15 minutes.
Cover each cup with plastic wrap and refrigerate for at least 3 hours or until set and jiggly like a soft custard.
Top with a few fresh berries just before serving. The possets keep well in the refrigerator covered for up to 4 days.