Japanese Sweet Potato Buns

Instructions

1. Prepare the sweet potato filling
   Peel the sweet potatoes and cut into 1-inch chunks. Steam or boil until completely tender, about 15-20 minutes. Drain well and mash until smooth. Mix in condensed milk, honey, and 1 tablespoon butter while still warm. Allow to cool completely before using.
2. Make the dough
   In a large bowl, whisk together bread flour, sugar, salt, and yeast. In a separate bowl, combine warm milk and egg. Pour the wet ingredients into the dry ingredients and mix until a shaggy dough forms. Add the softened butter and knead for 8-10 minutes until smooth and elastic. The dough should be slightly tacky but not sticky.
3. First rise
   Place the dough in a lightly greased bowl, cover with plastic wrap or a damp cloth, and let rise in a warm place for about 1 hour, or until doubled in size. Meanwhile, line a baking sheet with parchment paper.
4. Shape the buns
   Punch down the dough and divide into 10 equal pieces (about 80g each). Roll each piece into a ball, then flatten into a 4-inch disc. Place 1-2 tablespoons of sweet potato filling in the center of each disc. Bring the edges up and pinch to seal completely. Place seam-side down on the prepared baking sheet, leaving about 2 inches between each bun.
5. Second rise
   Cover the shaped buns with a damp cloth and let rise for another 30-40 minutes, until puffy. Preheat the oven to 350°F (175°C) during the last 10 minutes of rising.
6. Bake the buns
   Gently brush the tops of the buns with egg wash. Bake for 18-22 minutes, until the tops are golden brown and the buns sound hollow when tapped on the bottom. Transfer to a wire rack to cool slightly before serving.