01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Heat a large skillet over medium heat and cook the ground beef until well browned, breaking it up as it cooks. Drain excess fat as needed.
03 - Add chopped onion, green bell pepper, and minced garlic to the skillet. Cook for 3–4 minutes until the vegetables are softened.
04 - Stir in tomato sauce, tomato paste, ketchup, Worcestershire sauce, smoked paprika, brown sugar, salt, black pepper, and dried oregano. Simmer the mixture for 8–10 minutes until thickened, then remove from heat.
05 - Slice the baguette horizontally. In a small bowl, blend softened butter with minced garlic, chopped parsley, and 1/4 teaspoon salt.
06 - Spread garlic butter evenly across both cut halves of the bread. Arrange the halves, cut side up, on the prepared baking sheet.
07 - Bake for 5–6 minutes until lightly golden. Remove from the oven.
08 - Top one half of each bread piece with a generous layer of the sloppy joe filling. Sprinkle mozzarella and Parmesan cheese evenly on top.
09 - Return to the oven for 5–6 minutes, or until cheese is melted and bubbly.
10 - Place the remaining bread halves on top to form sandwiches. Press gently, slice into portions, and serve while hot.