1-First, preheat the oven to 350°F and line a baking sheet with parchment paper. Slice the 1 loaf Italian bread lengthwise into two halves and place them cut side up on the baking sheet. Mix the ½ cup softened unsalted butter and 1 teaspoon garlic salt, then spread it over the bread halves.

2-In a medium skillet over medium heat, cook the 1 pound ground beef and ¼ cup chopped yellow onion until the beef is no longer pink, about 8-10 minutes; drain the grease. Add the ½ teaspoon garlic powder, 1 teaspoon yellow mustard, ¾ cup ketchup, ½ teaspoon kosher salt, ¼ teaspoon black pepper, and ½ cup water; stir to combine.

3-Divide the sloppy joe mixture between the two bread halves and top with the 1 cup shredded mozzarella cheese and 1 cup shredded sharp cheddar cheese. Bake for 12-14 minutes until golden brown. For an optional air fryer method, follow all steps up to adding the toppings, then place the bread in an air fryer basket and air fry at 400°F for about 5 minutes until the cheese is melted and golden brown.

4-Once baked, cut into pieces and garnish with the chopped parsley before serving.