In a mixing bowl, combine flour, sugar, salt, and yeast.
Add warm milk and egg to the dry ingredients. Mix until a dough forms.
Add softened butter and knead the dough until smooth and elastic.
Cover the dough and let it rise for about 1 hour or until doubled in size.
Meanwhile, prepare the topping by beating the butter and sugar until light and fluffy.
Add the egg and dissolved coffee to the butter mixture and mix well.
Gradually add the flour and mix until smooth. Set aside.
Once the dough has risen, punch it down and divide it into 8 equal portions. Shape each portion into a ball.
Place the dough balls on a baking sheet lined with parchment paper. Let them rise for another 30 minutes.
Preheat the oven to 375°F (190°C).
Pipe the coffee topping in a spiral pattern on top of each dough ball.
Bake in the preheated oven for 15 minutes or until golden brown.
Remove from the oven and let cool slightly before serving.