1. Cut lemons in half and using a knife carefully cut around the flesh. Use a spoon to gently remove the lemon flesh from each lemon half, being careful not to tear the skins. Set aside the hollowed-out lemons (lemon shells), as you'll be filling them later.

2. In a small saucepan, heat the heavy cream over medium heat until it's hot but not boiling.
3. Once the cream is hot, add the powdered sugar, lemon zest, and lemon juice. Stir well to combine all the ingredients thoroughly.

4. Turn off the heat and carefully fill the lemon skins with the cream mixture.

5. Place the filled lemon skins in the refrigerator for 1-2 hours to allow the lemon posset to set.
6. Before serving, garnish each lemon posset with fresh mint leaves or fresh berries (like fresh raspberries or blackberries for extra flavor) and additional lemon zest.
7. To store this lemon dessert, cover it with plastic wrap or place it in an airtight container and refrigerate. Enjoy within a day or two for the best taste and texture.