01 -
Wrap the sweet potatoes in baking paper and aluminum foil. Bake in an oven preheated to 180°C for about one hour or until they become tender when pierced.
02 -
Remove sweet potatoes from the oven and place on a serving plate. Cut an oval opening at the top of each potato and carefully scoop out a small portion of the flesh. Mash the removed flesh with a fork and set aside.
03 -
In a mixing bowl, whisk together egg yolks, sugar, and cornstarch until smooth. Gradually incorporate the heavy cream while continuing to whisk until fully combined.
04 -
Transfer the mixture to a small saucepan and cook over medium heat, stirring constantly, until the custard thickens. For traditional Japanese consistency, keep it slightly fluid, or cook longer for a firmer texture, being careful not to curdle the mixture.
05 -
Immediately pour the warm custard into the hollowed sweet potatoes. Allow to cool slightly.
06 -
Sprinkle a thin, even layer of sugar over the custard surface and caramelize with a kitchen torch until golden brown and crisp.