Begin by freezing cubed salted butter for about 15 minutes to firm it up.

In a large bowl, combine the bread flour, instant yeast, milk powder, and sugar. Mix until well-blended.

Add in the eggs, cold water, and whipping cream. Mix until a shaggy dough forms.

Knead the dough on a floured surface for about 5 minutes until it becomes smooth and elastic.

Incorporate the unsalted butter and salt. Knead for an additional 6 minutes.

Place the dough in a lightly greased bowl and cover with a damp cloth. Let it rise for about 1 hour.

Punch down the dough to release air, divide it into 6 pieces weighing 50g each, and 6 smaller pieces of 15g. Rest for 10 minutes.

Flatten a small piece of dough and prepare to wrap the butter cube in it.

Encapsulate the butter with the larger piece of dough to promote buttery goodness.

For the coffee crust, combine coffee granules, cocoa powder, and a small amount of water to create a paste.

Cream unsalted butter with sugar, salt, and eggs until fluffy. Gradually add the all-purpose flour.

Preheat your oven to 190°C (375°F). Pipe the coffee mixture onto the buns and bake for 12-15 minutes.