This easy lemon posset is made with just cream, sugar, and lemon juice. It’s rich, silky, and full of bright citrus flavor—perfect for a make-ahead dessert that feels fancy but comes together in minutes.
In a medium saucepan, combine the cream and sugar. Bring to a gentle boil over medium heat, stirring often. Once it reaches a boil, reduce the heat slightly and let it simmer for 8–10 minutes, stirring occasionally. It should reduce a bit and thicken slightly.
Remove from the heat and stir in the lemon juice and zest (if using). Let it sit for 10 minutes to cool slightly and begin to set.
Strain the mixture through a fine mesh sieve into a spouted measuring cup to catch any zest or curdled bits.* Pour into individual jars, glasses, or ramekins (4- to 6-ounce capacity).
Chill uncovered for about 1 hour, then cover and chill at least 4 hours or overnight until fully set.
Serve cold, topped with your desired garnishes.
Notes
I recommend pouring into a measuring cup so you know what volume you have for dividing into servings. You should expect to get 1 1/2 to 1 2/3 cups in total.
Store tightly covered in the refrigerator up to 3 days.