Better-for-you cupcake feat: not-too-sweet sourdough chocolate cake filled with homemade taro paste and topped with an Okinawan sweet potato cream cheese frosting.
I rarely make cakes, but this was a fun little bake that shines on the natural flavors and colors of two of my favorite yummy Asian root veggies: taro and Okinawan (purple) sweet potato.
Baking Schedule
This recipe involves making everything from scratch: the cake, the filling, and the frosting. Because of this, it is quite time and labor-intensive. I recommend preparing the filling and frosting in advance, so on the day of baking, you only need to make and assemble the cake.
While it’s possible to purchase taro paste from the store to save time, I find that store-bought taro paste tends to be too sweet. In keeping with the theme of “not-too-sweet,” and assuming you like your pastries that way, I highly recommend making the taro paste from scratch.
Day before bake-day
? Make the Taro Paste
- 400g of taro, cubed
- 90g sugar
- 20g canola or coconut oil
Steam 400g taro (cubed) until the taro is fork tender. Transfer the taro to a food processor, add 90g sugar, and blend until smooth. Then, transfer the paste to a skillet and cook on medium to low heat, stirring constantly until the taro paste consistency is similar to mashed potatoes. This helps dissolve the sugar and bring out the natural nutty-ness of the taro. If the taro paste is too dry, you can add more water. Near the end of cooking, mix in 20g of canola or cocout oil. This will give the taro paste a smooth mouthfeel and a glossy finish. Transfer the taro paste to an air-tight container and store in the fridge until we are ready to assemble the cupcake.
? Okinawan sweet potato cream cheese frosting
- 60g Okinawan sweet potato (about 1 potato)
- 60g cream cheese
- 25g Greek yogurt
- 50g powdered sugar
Rinse the Okinawan sweet potato with water and wrap it in aluminum foil. Place it in the oven, preheat to 350°F, and bake for about 30 minutes. Then, turn off the oven and let the sweet potato cool completely inside. This allows the sweet potato to continue slowly cooking and caramelizing, acquiring a sweeter, nuttier flavor.
Once the sweet potato has completely cooled, unwrap it and carefully peel off the skin. Mash 60g of the Okinawan sweet potato in a stand mixer and add 60g of cream cheese, 25g of Greek yogurt, and 50g of powdered sugar. Mix on medium-high speed until a smooth and thick frosting forms. Transfer the frosting to an airtight container and store it in the fridge until you are ready to assemble the cupcakes.
Bake Day
? Not-too-sweet sourdough chocolate cake
- 100g sourdough discard
- 10g hot water + 1 tsp instant coffee powder
- 60g Greek yogurt
- 1 egg
- 1/3 tsp vanilla extract
- 36g vegetable oil
- 50g sugar
- 1/3 tsp salt
- 36g AP flour
- 25g cocoa powder
- 1/3 tsp baking powder
- 1/2 tsp baking soda
Dissolve instant coffee in hot water, cool, and then mix in the remaining wet ingredients. Combine all the dry ingredients and blend them into the wet mixture.
Evenly distribute the cupcake batter into 8 muffin liners. Using a small ice cream scoop, add a light scoop of taro paste in the center of the batter. Bake the cupcakes at 350°F until a toothpick inserted into the chocolate cake batter comes out clean. Allow the cupcakes to cool completely.
?️ Assembly
- remainder of the taro paste
- all of the Okinawan sweet potato cream cheese frosting
- 8 cupcakes
Using a small ice cream scooper, generously top the cupcakes with one scoop of taro paste. Finish by pipping the cream frosting around the taro paste using an open star tip.
Looking for more recipe ideas? Check these out:
- Taro Shortbread Bites
- Black Sesame & Banana Chiffon
- Black Sesame Banana Bread
- Sourdough Ube Crumble Sweet Rolls
Not-too-sweet Taro Filled Sourdough Chocolate Cake with Okinawan Sweet Potato Frosting
Equipment
- silicone cupcake liners or tin with liner
Ingredients
Taro Paste
- 400 g taro root, cubed
- 90 g sugar
- 20 g canola or coconut oil
Okinawan sweet potato cream cheese frosting
- 60 g Okinawan sweet potato
- 60 g cream cheese
- 25 g Greek yogurt
- 50 g powdered sugar
Not-too-sweet sourdough chocolate cake
- 100 g sourdough discard
- 10 g hot water
- 1 tsp instant coffee
- 60 g Greek yogurt
- 1 egg
- 1/3 tsp vanilla extract
- 36 g vegetable oil
- 50 g sugar
- 1/3 tsp salt
- 36 g all purpose flour
- 25 g cocoa powder
- 1/3 tsp baking powder
- 1/2 tsp baking soda
Instructions
Make the taro paste ahead of time
- Cut the taro into cubes and steam the taro until the taro is fork-tender.
- Using a food processor, blend the taro with sugar until it is a smooth paste. Then, transfer the taro paste to a skillet and cook on medium-low heat to dissolve the sugar and bring out more of the taro's natural nutty-ness. The taro paste should have a consistency similar to mashed potatoes, if it is too dry, you can add more water, if it is too wet, continue cooking until the paste thickens. At the end, mix in the canola/coconut oil. This will give the taro paste a smooth mouthfeel and a glossy finish.
- Transfer the taro paste to a bowl, cover with plastic wrap, and let it cool completely. Cover and refrigerate if not using immediately.
Okinawan sweet potato cream cheese frosting
- Rinse the Okinawan sweet potato with water and wrap the sweet potato in aluminum foil. Toss it in the oven and bake it for about 30 minutes. Turn the oven off and let it cool completely in the oven, the potato will continue to cook a caramelize.
- Peel and mash about 60g of the sweet potato. In a stand mixer, combine the rest of the frosting ingredients and mix it on high until a smooth and thick frosting forms. Cover and refrigerate if not using immediately.
Make the cake & frosting
- Preheat the oven to 350F
- Dissolve instant coffee in hot water and set aside. Mix together all the dry ingredients and set aside. Mix together all the wet ingredients and sugar with the instant coffee.
- Combine the dry ingredients with the wet until a smooth even batter forms. Evenly distribute the cake batter into 8 muffin liners.
- Using a small ice cream scooper, add a light scoop of taro paste into the center of the batter.
- Bake the cupcakes at 350F until a toothpick inserted into the chocolate cake batter comes out clean. Remove the cupcake from the oven and let it cool completely.
Assemble the cupcake
- Using a small ice cream scooper, generously top each of the cupcakes with one scoop of taro paste.
- Assemble a pipping bag with a star tip. Fill the pipping bag with the Okinawan cream cheese frosting and pipe the frosting all around the taro paste.
- Store in the fridge and enjoy within 3 days.
