Step 1

Finely grate the zest of 1 large lemon (about 1 tablespoon). Juice the zested lemon plus one more as needed until you have 1/4 cup. If using a vanilla bean, cut in half lengthwise. Scrape the back of a paring knife along the cut side of each half to scrape out the seeds.

Step 2

Place the lemon zest, vanilla bean pod and seeds (or 1 teaspoon vanilla extract), 2 cups heavy cream, 2/3 cup granulated sugar, and 1/4 teaspoon kosher salt in a medium saucepan over medium heat. Bring to a simmer, stirring until the sugar is dissolved. Reduce the heat to medium low, stirring constantly, and simmer until the mixture begins to thicken, 3 to 5 minutes. Add the lemon juice and stir to combine.

Step 3

Remove the pan from the heat and let sit until cooled to room temperature, 20 to 30 minutes. Remove the vanilla bean pod if using. Stir and transfer the mixture to a liquid measuring cup.

Step 4

Pour and divide the mixture between 4 (4-ounce) ramekins or small bowls. Refrigerate uncovered until set, at least 2 hours. Serve chilled topped with fresh raspberries or macerated strawberries if desired.