01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large skillet over medium heat, cook ground beef until browned, breaking it up with a wooden spoon. Drain excess fat as needed.
03 - Add onion, green bell pepper, and minced garlic to the skillet. Sauté for 3 to 4 minutes until vegetables are softened.
04 - Add tomato sauce, tomato paste, ketchup, Worcestershire sauce, smoked paprika, brown sugar, salt, black pepper, and dried oregano. Stir to combine. Simmer for 8 to 10 minutes until thickened. Remove from heat.
05 - Slice the baguette in half lengthwise. In a mixing bowl, combine softened butter, minced garlic, chopped parsley, and 1/4 teaspoon salt.
06 - Spread the prepared garlic butter evenly over both bread halves. Place cut side up on the lined baking sheet. Bake for 5 to 6 minutes until lightly golden. Remove from oven.
07 - Generously spoon the warm sloppy joe filling onto one half of each bread piece. Sprinkle with shredded mozzarella and grated Parmesan cheese.
08 - Return to the oven for 5 to 6 minutes, until cheese is melted and bubbly.
09 - Sandwich the top and bottom bread halves together, press gently, and slice into individual portions. Serve immediately while hot.