Zest and juice the lemons. You’ll want about 1/2 cup of freshly squeezed lemon juice and 1 to 2 teaspoons of zest. Avoid the white pith—it’s bitter.

Whisk the yolks and sweetener. In a medium, heatproof bowl, whisk 4 large egg yolks with 1/2 cup powdered erythritol or allulose until smooth and slightly lighter in color.

Add lemon and salt. Whisk in the lemon juice, zest, and a small pinch of salt until fully combined.

Cook the curd gently. Set the bowl over a pot of gently simmering water (double boiler method). Cook, whisking constantly, until the mixture thickens enough to coat the back of a spoon, about 7–10 minutes. Do not let it boil.

Add butter. Remove from heat and whisk in 4 tablespoons of room-temperature unsalted butter, a piece at a time, until fully melted and glossy.

Strain for silkiness. Press the curd through a fine mesh sieve into a clean bowl to remove any tiny bits of cooked egg and zest. This step keeps it ultra smooth.

Chill. Press plastic wrap directly onto the surface to prevent a skin from forming. Chill in the fridge for at least 1 hour, or until cool and thick.

Whip the cream. In a cold bowl, whip 1 cup heavy cream with 2–3 tablespoons powdered erythritol or allulose and 1/2 teaspoon vanilla until soft peaks form. Don’t overbeat.

Assemble. Spoon lemon curd into small jars or glasses, then add a layer of whipped cream. Repeat if you like, ending with cream. Garnish with zest, berries, or coconut.

Serve or chill. Enjoy right away or refrigerate for up to a day to set the layers. The flavors meld and become even better.