Stuffed Pretzel

Ingredients: 1 1/2 cups warm water (110°F/45°C) 2 1/4 teaspoons active dry yeast 1 tablespoon granulated sugar 4 cups all-purpose flour 1 teaspoon salt 4 tablespoons unsalted butter, melted 1 1/2 cups mozzarella cheese, cut into sticks 1/2 cup baking soda 9 cups water Coarse salt, for spr