In a small bowl, combine warm milk, sugar, and active dry yeast. Allow the mixture to sit for about 5-10 minutes until bubbly and frothy.

In a mixing bowl, combine bread flour, salt, and sugar. Create a well in the center, then pour in the yeast mixture, melted butter, and egg. Mix until a shaggy dough forms.

Transfer the shaggy dough onto a floured surface or into a stand mixer fitted with a dough hook. Knead the dough for 15-20 minutes until smooth and elastic.

Lightly oil a clean bowl and place the kneaded dough inside, turning it to coat in oil. Cover with a damp towel or plastic wrap. Allow to rise for 45-90 minutes, or until doubled in size.

Prepare the filling by mixing shredded coconut, melted butter, dry milk powder, sugar, all-purpose flour, and salt until crumbly and well-combined.

Punch down the risen dough and divide into 12-16 equal pieces. Shape each into a ball and let rest for 10 minutes.

Roll each dough ball into an oval, add coconut filling in the center, fold over, and seal tightly. Place seam-side down on a parchment-lined baking sheet.

Cover the buns and let rise for another 30-40 minutes while preheating the oven to 350°F (176°C).

Mix melted butter, all-purpose flour, and confectioner’s sugar for the topping. Brush buns with egg wash, pipe topping over each bun, optional sprinkle sesame seeds, and bake for 20 minutes until golden brown.

Remove buns from the oven and let cool on a wire rack for 10 minutes before serving.