Description
This Japanese Sweet Potato Pound features a plush and moist cake base, generously studded with sweet and salty sweet potatoes inspired by daigaku imo. Perfect for embracing the comforting flavours of autumn and winter!
Ingredients
Units
Scale
Sweet Potato
- 2 medium (375-400 g) Japanese sweet potato
- 3/4 cup (175 ml) water
- 5 tbsp (60 g) sugar
- 1 1/2 tbsp (20 ml) Japanese light soy sauce
- 1 1/2 tbsp (20 g) unsalted butter
- 2 tsp (10 ml) rum, optional
Cake
- 1/2 cup (112 g) room temperature butter (65 – 68 F / 18 – 20 C)
- 1/2 cup (100 g) granulated sugar
- 1/3 cup (85-90 g) room temperature eggs (68 – 72 F / 20 – 22 C)
- 1/2 tbsp (7 ml) mirin
- 1/2 tbsp (7 ml) Japanese soy sauce*
- 1 tsp (5 ml) vinegar
- 1/2 tbsp (7 ml) vanilla
- 1/4 cup (28 g) fine almond flour
- 1.5 tbsp (14 g) corn starch
- 1/2 cup + 2 tbsp (87 g) cake flour
- 1/2 tsp (2.8 g) baking powder
- black sesame seeds
Instructions
- Cook sweet potatoes: Cut the sweet potatoes into 1.5 – 2 cm inch pieces and soak in water for 15 minutes. Drain the potatoes. To microwave, add the potatoes back the bowl along with the water, sugar, butter, soy sauce and rum. The liquid should cover most of the sweet potatoes. Cover with plastic wrap and microwave for 5 minutes. Carefully remove the cover and turn the potatoes over and microwave for another 2-4 minutes, or until you can pierce a skewer through. To cook over the stove, add the potatoes to a pot (preferably with a wide base and not overlapping) along with the remaining ingredients and simmer on low heat for 15-20 minutes or until you can easily pierce a skewer through. Let the potatoes soak in the mixture while letting it cool. Tip: make the sweet potatoes the night before to allow the flavours to soak in more. Once cooled, remove the potatoes from the liquid and cut the larger pieces in half. Reserve this liquid to brush over the cake at the end (if it looks really watery, reduce it over heat until syrupy).
- Pre-heat oven to 375 F (190 C). Prepare loaf pan by lining or greasing and flouring. I use a 8 x 4 x 3.75 inch ((20 x 10 x 9.5 cm) and a base measurement of 7.2 x 3.4 inch (18.5 x 8.75cm)) for this amount of batter.
- Prepare batter: Add the eggs, mirin, soy sauce, vinegar and vanilla to a bowl and whisk to combine. Sift the flour, almond flour and baking powder to a bowl of a stand mix. Add the sugar and use the paddle attachment to mix on low speed until mixed. Scatter the room temperature butter into the bowl and mix on low speed until crumbly. Add 1/3 of the eggs and mix on medium high for 2 minutes. Stop and scrape down the sides of the bowl. On low speed, add another 1/3 of the eggs and mix for 30 seconds. Scrape down the sides and add the remaining 1/3 of eggs and mix for another 30-45 seconds, until smooth.
- Assemble: Add a bit less than half of the batter to the base of the loaf pan. Add a layer of sweet potatoes in random directions. Add the remaining batter on top and tap the pan on the counter to remove any excess air. Add remaining sweet potatoes on top. Tap the pan on the counter two more times to remove any air bubbles. Sprinkle with a generous amount of black sesame seeds.
- Bake: Reduce the temperature to 340 F (170 C) and bake for 65-80 minutes for 8 x 4 inch pan (60-70 minutes for 7.5 x 3.5 inch pan), or until internal temperature of the cake reaches 200 – 210 F (93 – 98 C). Remove from pan and transfer to wire rack. Once cool enough to handle, wrap with plastic wrap and refrigerate overnight.
- Serve: When ready to serve, brush the remaining syrup and enjoy!
Notes
- I used a 7.5 x 3.5 inch (18 x 8.5 x 8 cm) / base measurements: 2.8 x 6.7 inch (16.5 x 7 cm) loaf pan in the photos with adjusted amounts. I’ve scaled the recipe to fit a standard 8 x 4 inch loaf tin that most people have.
- Prep Time: 20 minutes
- Cook Time: 65 minutes
- Category: Dessert
- Method: Baking
- Cuisine: Japanese