Preheat your oven to 325°F (163°C). Gather your ramekins and baking dish.

In a mixing bowl, whisk together the cooked and mashed sweet potatoes, sugar, heavy cream, egg yolks, and vanilla extract until smooth.

Pour the custard mixture into the ramekins, filling them about three-quarters full. Place ramekins in a baking dish and fill the dish with hot water to halfway up the sides of the ramekins.

Bake for 30-40 minutes until the custards are set with a slight jiggle in the center.

Remove the ramekins from the water bath and let them cool at room temperature before refrigerating for at least 2 hours.

Before serving, sprinkle a thin layer of sugar over each custard and caramelize using a kitchen torch or under a broiler.