Preheat your oven to 375°F (190°C). Line a large baking sheet with parchment paper.

Slice the French bread loaf in half lengthwise. Using your fingers or a small spoon, gently scoop out some of the soft interior from both halves, leaving about a half-inch border to create shallow 'boats' or trenches for the filling.

If using the butter and garlic powder mix, brush it lightly over the scooped-out interiors of both bread halves. Bake the hollowed bread shells for 5 minutes to toast while preparing the meat.

While the bread toasts, heat the oil in a large skillet over medium-high heat. Add the ground beef and cook, breaking it up with a spoon, until evenly browned, about 5-7 minutes. If adding onion and bell pepper, add them after the beef is mostly browned and cook for another 3-4 minutes until softened.

Drain off any excess grease from the skillet. Return the meat mixture to the skillet and stir in the sloppy joe sauce, salt, and pepper. Simmer for 2 minutes to blend flavors. If too thick, add a splash of water; aim for a thick consistency.

Remove the bread from the oven. Sprinkle half of the shredded cheese evenly into the bottom of both bread halves to create a barrier.

Spoon the sloppy joe mixture over the cheese layer, pushing it gently into the hollowed-out space.

Sprinkle the remaining cheese over the top. Bake for 8-12 minutes, or until the cheese is melted, bubbly, and golden, and the bread crust is crispy.

Let cool for 2-3 minutes, then slice into 2-inch wide pieces using a serrated knife. Garnish with chopped parsley or green onions if desired. Serve immediately.