Preheat the oven. Heat oven to 325°F (160°C). Place 4 oven-safe ramekins in a deep baking dish.

Warm the cream. In a saucepan over medium heat, combine heavy cream, vanilla bean seeds (and pod, if using), and salt. Heat until just steaming, do not boil. Remove from heat and let steep for 5 minutes.

Mix the yolks and sweetener. In a medium bowl, whisk egg yolks and erythritol until pale and slightly thickened.

Temper the eggs. Slowly pour the warm cream into the yolk mixture, whisking constantly to prevent scrambling.

Fill the ramekins. Strain custard through a fine-mesh sieve into the ramekins for an ultra-smooth texture.

Bake in a water bath. Pour hot water into the baking dish until it reaches halfway up the ramekins. Bake for 30–35 minutes, until custards are set but still slightly jiggly in the center.

Cool and chill. Remove from oven, cool to room temperature, then cover and refrigerate at least 2 hours (or overnight).

Caramelize the tops. Just before serving, sprinkle 1–2 teaspoons sweetener over each custard. Torch (or broil briefly) until golden and crisp.

Serve and enjoy. Crack through the golden crust and savor the creamy custard beneath.