Sweetened Adzuki Beans
1. Rinse and drain the beans, then transfer to a medium pot. Add fresh, cold water, enough to cover the beans by 3 inches. Bring to a boil and cook uncovered for 10 minutes. Then reduce the heat as low as the stovetop will go, cover, and cook for 45 minutes or until tender. 

2. Reserve about 1 cup of the bean liquid and drain the rest. Return the cooked beans to the pot and mix in the brown sugar, honey, and salt. Once everything has incorporated, add 1/2 cup of the reserved bean liquid. 

3. Place the pot over medium heat. Bring to a boil, then reduce heat to a simmer. Cook for about 8-10 minutes, stirring once in a while to let the contents reduce. The beans are done with they resemble a thick chili-like stew. If the bean mixture looks too dry, add a little bit of the bean water to get the right consistency. 

4. Place in a clean bowl or heatproof container. Cool completely before using. Sweetened adzuki beans can be made up to 3 days in advance and kept in the refrigerator. 

Peanut Streusel*
1. In a bowl, cream the butter and peanut butter until smooth. Add the sugar and mix until incorporated. Add the yolk and vanilla extract and combine. Add the all purpose flour, baking powder, and cornstarch and mix until a cohesive dough forms.

2. Break the dough apart into small crumbly, pieces. Cover and set aside at room temperature until needed.

Flour Paste/Tangzhong
1. In a microwave safe bowl, whisk the water and bread flour together until there are no lumps. Microwave at 20 second intervals, whisking in between, until the mixture is thick and smooth like a pudding.

Dough
1. In the bowl of a stand mixer, add the cooked flour paste/tangzhong and slowly whisk in the milk. Whisk in the egg and mix until smooth. Add the bread flour, sugar, salt, and yeast and mix with a spatula.

2. Once the dough roughly comes together, place the dough hook on the stand mixer and mix on medium low speed for 5 minutes.

3. Fold in the butter by hand. Once the butter is roughly incorporated, continue kneading with the dough hook on medium low for 5 minutes.

4. Flour your hands and form the dough into a ball. Transfer to a bowl that’s been lightly greased with oil. Cover and set aside in a warm place. Let rise for 40 minutes to 1 hour and 15 minutes or until doubled in size. To test if it’s ready, flour your index finger and press into the dough, like you’re poking someone. If the dough springs back, let it rise for a little longer. If the indentation remains, the dough is ready. 

5. Line two baking sheets with parchment paper.

6. Once the dough has doubled in size, divide the dough into 10 equal pieces (around 50 g each in weight). Shape each piece into a smooth round. If the dough feels too sticky, coat your hands in flour. Let rest for 10-15 minutes.

7. Meanwhile, get the sweetened adzuki beans. Divide into 10 equal portions (around 50 g each in weight) and form into a tight ball.

8. In a small bowl, mix 1 cup water with 1 teaspoon cornstarch.*

9. Generously flour your hands. Get one piece of dough and flatten into a large disk. Place one adzuki bean ball in the middle. Pinch the sides of the dough to seal. Repeat until all the dough pieces have been filled. 

10. Scoop two heaping tablespoons of peanut streusel on the countertop. Dip the smooth side of the stuffed dough into the water-cornstarch mixture. press the wet part of the dough into the streusel, flattening the round dough into a disk shape. Make sure to stick as much of the streusel onto the dough as possible. Repeat. 

9. Place five pieces of dough on each baking sheet. Carefully reshape each dough into a circle if needed. Loosely cover with plastic wrap and let rise in a warm place for 40 minutes to 1 hour.

10. Preheat oven to 375 degrees or 190 degrees C.

11. Bake for 13-15 minutes, rotating sheets halfway through baking, or until lightly golden. Cool on a rack and enjoy warm or at room temperature. Store in an airtight container for 1 day, or in the fridge for about 1 week.