01 - Preheat the oven to 400 degrees Fahrenheit. Line a baking sheet with parchment paper to prevent sticking.
02 - In a large skillet over medium heat, cook the ground beef, breaking it apart with a spatula, until browned. Drain excess fat as needed.
03 - Add chopped onion, green bell pepper, and minced garlic to the skillet. Sauté for 3 to 4 minutes until vegetables are tender.
04 - Stir in tomato sauce, tomato paste, ketchup, Worcestershire sauce, smoked paprika, brown sugar, salt, black pepper, and oregano. Simmer for 8 to 10 minutes until the filling thickens. Remove from heat.
05 - In a small mixing bowl, combine softened butter, minced garlic, chopped parsley, and salt until thoroughly blended.
06 - Slice the baguette lengthwise. Spread garlic butter evenly over the cut sides of both bread halves. Place face up on the prepared baking sheet.
07 - Bake in the preheated oven for 5 to 6 minutes or until lightly golden. Remove the tray from the oven.
08 - Generously spoon the warm sloppy joe filling onto the bottom half of the bread. Sprinkle with mozzarella and Parmesan cheese.
09 - Return the assembled bread to the oven for another 5 to 6 minutes, until the cheese is fully melted and bubbling.
10 - Sandwich the top bread half over the filling, press gently, and slice into individual servings. Serve hot.