Grate mozzarella cheese and yellow cheese and set aside.
In a bowl, mix flour, yeast, sugar, and salt.
Add milk and eggs to make a dough.
Add room-temperature butter and knead the dough until smooth.
Let the dough rise for the first proofing.
Divide the risen dough and shape it into balls.
Place grated yellow cheese and mozzarella cheese on top of the dough.
Line a pan with parchment paper, place the dough on it, and let it rise for the second proofing.
Bake in a preheated oven at 180°C for 20 minutes.