One of the highlights of visiting a Japanese cake shop in autumn is the simple treat called スイートポテト (suito poteto), or sweet potato in English. However, it’s not the sweet potato you have in mind. It combines butter and milk, or cream, with sweet potatoes to make a palm-sized, almond-shaped cake with a consistency similar to cheesecake.
And I’m going to help you make some at home just in time for Halloween.
Based on my cooking adventure detailed below, I can tell you that that patisserie-grade smoothness found at Japanese pastry shops likely requires a food processor. Still, with no flour and lots of fiber, these are relatively healthy treats that are an excellent way to celebrate the season at home, even if they end up a little chunky.
You will probably already have most of the ingredients for this recipe in your kitchen, but deciding what kind of sweet potato you will use is worth some consideration. If you want it sweet and don’t want to add sugar, use the sweetest sweet potato you can find: 安納芋 (annou imo).
It’s from Tanegashima in southern Kagoshima Prefecture, and you will find it in most supermarkets from mid-October through January. It will likely cost a bit more than the regular variety 薩摩芋 (satsuma imo).
Maximize the sugar content of your potatoes by simmering them over low heat. If you’re not fussed about sweetness or happy to throw in some sugar, you could microwave them instead of steaming them. Either way, be sure to cook the sweet potato until very soft, particularly if you don’t have a food processor and will have to mash them like me.
- Sweet potato (200g)
- Butter (20g)
- Milk (20g, varies depending to your cooked potatoes’ moisture content)
- Sugar, rum (to taste)
- Egg (a small amount to brush the cakes)
- Chocolate pen for decorating
- Peel the sweet potato, cut it into pieces and steam it. Cook until very soft (at least 15 minutes).
- Mix the butter and milk into the sweet potato, with a food processor if you have one, or by mashing. Add sugar and rum, as you like.
- Divide the mixture into six even amounts and shape them into cakes. Wet your hands before shaping the mix so that it doesn’t stick to them.
- Brush each cake with a small amount of beaten egg.
- Cook on low heat under a grill or a horizontal toaster until browned.
- Decorate as desired
I used the シルクスイート (silk sweet) variety of sweet potato and added about 2⅓ tablespoons of sugar and a few splashes of brandy, rather than rum because that was what was in the cupboard.
So, how did it come out?
Since I don’t have a food processor, I couldn’t achieve the smooth consistency that I would have preferred. The cakes taste great, though, with a mild sweetness.
I was hoping the finished product would be wildly adorable, but for a chef who lacks the Japanese kawaii gene, they were a little… cute. In hindsight, after far too much consideration about whether I should give the ghosts arms or not, they probably would have looked better with them.
My daughter and I used a chocolate pen to decorate the ghosts. The brown chocolate is hard to see on some of the more toasted cake sections, so white chocolate would probably work better. We used a clean, old yakitori (grilled chicken) skewer to get our designs just right. You could use sultanas and pumpkin seeds for decoration, instead. Or you could just shape the sweet potato into balls.
Since the steps in this recipe are all very simple, it’s a good one to make together with children. They would particularly enjoy molding and decorating the ghosts, and it’s a great activity if they’ll be celebrating Halloween at home this year.
Hungry? Check out more of our Japanese Recipe Adventure series. Let us know what recipe you’d like to see us try next in the comments!