In a bowl, whisk water, sugar, yeast, and salt.

Then, mix in high-gluten flour and melted butter.

Knead for 5 minutes and let it double in size for an hour. Cover the bowl with a cling wrap.

Next, make the puff pastry by mixing butter, brown sugar, white sugar, egg yolk, low-gluten flour, and baking powder. You can add the flour and baking powder last after mixing the other ingredients first.

Refrigerate the puff pastry for 10 minutes.

Once the fermented dough increases in size, divide it into 6 parts, shape it into small balls, and let them double in size again. Cover the dough balls again with a cling wrap.

Afterward, divide the puff pastry into 6 portions as well and use a rolling pin to flatten each portion into thin circular sheets. To prevent sticking, you can place plastic wrap both above and below the puff pastry as you roll it out.

When the dough balls increase in size again, cover each dough portion with puff pastry.

Place the assembled buns in the baking tray lined with parchment paper.

Brush each bun with egg yolk wash. Although this can be optional, I highly recommend coating the top crust with egg wash to give you that shiny and beautiful brown crust after baking. Brush the edges and the top with this.

To make egg yolk wash, mix a whole egg, egg yolk, or egg white with a little bit of water or milk.

Preheat the oven. Bake at 180°C for 16 minutes until golden brown.