Preheat oven to 350 degrees F and grease a 9x5 inch loaf pan.

Melt the unsalted butter in a small saucepan over low heat, then remove from heat and stir in the minced garlic and chopped fresh rosemary.

Roll out the bread dough on a flat surface and cut it into 3-inch squares.

Brush each dough square with the herb butter mixture and sprinkle evenly with the mozzarella and parmesan cheeses.

Stack the squares together and place them upright in the prepared loaf pan. Top with any remaining butter and the flaky sea salt.

Bake for 30 to 35 minutes until golden brown and cooked through. Cool for 10 minutes before serving.