In a mixing bowl, combine warm milk, sugar, and yeast. Let it sit for 5 minutes until frothy.

Add melted butter, salt, and flour to the yeast mixture. Mix until a dough forms.

Knead the dough on a floured surface for about 5 minutes until smooth.

Place the dough in a greased bowl, cover with a cloth, and let it rise in a warm place for 1 hour or until doubled in size.

Preheat the oven to 375°F (190°C).

Once the dough has risen, punch it down and fold in the mozzarella cheese.

Shape the dough into a loaf and place it on a baking sheet lined with parchment paper.

Sprinkle the top with cheddar cheese and parsley if using.

Bake for 25-30 minutes until golden brown and the cheese is bubbly.

Let it cool for a few minutes before slicing and serving.