I literally only came up with this recipe because I had a lot of leftover sweet potato paste from making the hiyoko manju. I also had a cake order for a chocolate cake, and whenever I make my layer cakes, I always end up with a decent amount of cake scraps. So with leftover sweet potato paste and leftover chocolate cake, I had to do something to use them up, since I didn’t want to just throw them out. When it came to the sweet potato in particular, I thought about doing more wagashi, but then I remembered something I watched on Unique Sweets back when I was in high school – a doughnut store used mashed potatoes in their doughnuts to create a light, fluffy, and buttery texture. So right away, I thought about using the paste in a yeast-leavened dough to do the same thing. Then with the chocolate cake scraps, my initial thought was either make an ice cream or do cake balls. But been there, done that, and I don’t really even like cake balls(the idea of cake mashed with buttercream just sounds wrong to me) that much, so not going that route. But then I remembered babka. A braided yeast leavened bread dough, similar to brioche, that enrobes this decadent chocolate filling that is thickened traditionally with chocolate cookies. In place of the cookies, I figured, let’s just use the cake. It’s a flour-based item like a cookie, is chocolate flavored, and can easily be used to thicken something.

So slowly but surely, the idea for this recipe came together. A sweet potato based bread or brioche dough, with a decadent chocolate filling. Personally, I did not want to do another babka, just because it is extremely finnicky and time-consuming, so I opted for the simpler sticky bun. I figured drowning the baked buns in a miso butterscotch, and adding in some dulcey(blonde chocolate)-blended walnuts for texture would round out these buns and make them a salted caramel-chocolate-type of experience. Truthfully, the usage of the sweet potato is completely optional(just sub it out with 1 cup flour if you don’t want to use it), but it did provide the dough with a very soft texture. That and I was trying to get rid of it, so it worked perfectly in this recipe. With these buns, they are perfect for breakfast, dessert, or a snack, or all three if you are feeling saucy and adventurous like you should, since life is short anyways.

For the dough:
1 packet active dry yeast
1 tablespoon granulated sugar
1/4 cup lukewarm water
2 eggs
a pinch of salt
1 cup all-purpose flour
8oz mashed yam or sweet potato
4 tablespoons unsalted butter

Mix yeast with sugar and water and allow that to sit for 10 minutes. Combine with eggs, salt, flour, and mashed sweet potato and start mixing. Incorporate the butter, one tablespoon at a time, into the dough, continuously kneading the dough until it is completely smooth and comes off any surface cleanly. Refrigerate the dough for 2 hours.

For the dulcey walnuts:
1/2 cup roasted walnuts
1/4 cup blonde chocolate
a pinch of salt

In a food processor, puree everything into a fine powder. Keep in an airtight container.

For the filling:
1/2 cup chocolate cake or chocolate cookies
1/2 cup dark chocolate chips
1/2 cup milk
a pinch of salt

Puree in a blender or food processor until it forms a smooth paste. On a floured surface, roll out the dough into a 1 ft by 2 ft rectangle, and spread on the chocolate filling. Sprinkle on half of the walnuts in an even layer as well. Roll up the dough to form a log, and freeze for at least 45 minutes. Cut into 12 pieces, and transfer into a parchment-lined baking tray. Proof for another hour at room temperature, then bake at 350 degrees F for 25 minutes.

For the butterscotch:
1/2 cup dark brown sugar
1 tablespoon miso paste
4 tablespoons unsalted butter
1/2 cup water

Bring everything to a simmer and allow it to reduce until what’s left is a glaze-like caramel. Pour over the buns and sprinkle on your remaining walnut crumb.