Yakiimo Crème Brûlée is a fusion dessert that marries the comforting flavors of roasted Japanese sweet potatoes (yakiimo) with the luxurious, creamy texture of classic French crème brûlée. This unique creation offers a captivating blend of traditional and modern culinary elements, making it a standout treat popular especially in Tokyo.
Yakiimo is blended together with eggs yolks and sugar to create a creamy custard filling that is then coated in sugar and torched to create a crispy caramel layer on top.
To make yakiimo itself, whole Japanese sweet potatoes are slow-roasted over hot stones or in wood-fired ovens. This traditional method brings out their natural sweetness and results in a caramelized exterior and a soft, fluffy interior.
Yakiimo is a popular street food, especially during the colder months, with vendors often peddling their wares from trucks equipped with wood-burning stoves.
What is Yakiimo?
Yakiimo literally means “roasted potato,” and it refers specifically to Japanese sweet potatoes (“satsumaimo” in Japanese) that are slowly roasted until the inside becomes soft, creamy, and naturally sweet. The skin gets slightly crisp and caramelized, while the flesh turns golden, fluffy, and sometimes sticky with natural sugars.
Traditional yakiimo is roasted over hot stones (ishiyakiimo, 石焼き芋) in a specially outfitted truck or vendor stand. The low-and-slow roasting technique allows the starches in the sweet potato to convert into sugars, creating a rich, honey-like sweetness. In colder months, especially in the countryside or suburbs of Japan, you might hear a nostalgic chant: “Ishiyaki-imo, yaki-imo~…”
These trucks roam neighborhoods selling hot sweet potatoes, just like ice cream trucks, but in the winter. Obviously roasting over hot stones is not accessible to most people, so you can make yakiimo at home using ovens, air fryers, or even toaster ovens—slow-roasting for 60 – 90 minutes.
Tools to Make Yakiimo Crème Brûlée
Here’s a bullet-point breakdown of the two main tools you’ll want if you’re making Yakiimo Crème Brûlée:
- Ramekins (optional)
- Use if you scoop out the sweet potato flesh to make a custard-like filling or serve it more refined.
- Great for even portioning.
- Helps create a smooth surface for torching the sugar topping.
- Optional: You can skip ramekins and serve directly in the halved yakiimo skin for a rustic, charming presentation.
- Blow Torch (essential for brûlée style)
- Caramelizes sugar into that crackly, glassy top layer.
- Quick and easy to control heat without overbaking the sweet potato underneath.
- Small kitchen torches are inexpensive and super versatile (great for marshmallows, cheese, or charring peppers too!).
Yakiimo Crème Brûlée
- Total Time: 115 minutes
Description
Yakiimo crème brûlée is a delightful fusion dessert combining the creamy richness of crème brûlée with the earthy sweetness of Japanese roasted sweet potatoes.
Ingredients
- 1 large Japanese sweet potato
- 1/2 cup heavy cream
- 1/8 cup sugar
- 1 egg yolk
- 1 teaspoon corn starch
- 2 tablespoons butter
- 1/2 tablespoon sugar (for topping; use more or less as needed)
Instructions
- Preheat oven to 375°F (190°C).
- Place the Japanese sweet potato directly on the oven rack and bake for 90 minutes.
- In a small pot over medium heat, combine heavy cream and 1/8 cup of sugar. Bring to a simmer for 5 minutes. Remove from heat.
- Remove the Japanese sweet potato from the oven. Carefully cut a slit across the sweet potato (longways) and remove about 3/4 of the fillings, placing into a small bowl.
- In that same bowl, whisk together the filling, egg yolk, and corn starch until well combined.
- Optional: If you want an extra-smooth, creamy consistency (with no sweet potato chunks), pass the sweet potato mixture through a fine-mesh sieve or tamis using a spatula or spoon.
- Over low heat, slowly pour the sweet potato mixture into the pot with the cream, stirring constantly.
- Add the butter, stirring until thickened, and the filling is smooth in consistency.
- Pour the creamy filling into the hollowed-out Japanese sweet potato (or your ramekin if you are using that instead). Sprinkle sugar on top and use a torch to caramelize the sugar.
- Prep Time: 15 mintues
- Cook Time: 90 minutes
Nutrition
- Serving Size: 1-2
I will take any dessert that is healthier than the original! How much sweet potato do you keep?
Me too! It just depends on how big your sweet potato is but I just eat whatever is not used for this plain 🙂 so good1
The roasted sweet potato gave the custard an earthy sweetness that really worked.
Yum! That custard is so good! Thanks for sharing, Jocelyn! 🙂