01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large skillet over medium heat, cook the ground beef, breaking it apart with a spoon, until browned. Drain excess fat if needed.
03 - Add the chopped onion, bell pepper, and minced garlic to the beef. Sauté for 3 to 4 minutes until softened.
04 - Incorporate tomato sauce, tomato paste, ketchup, Worcestershire sauce, smoked paprika, brown sugar, salt, black pepper, and dried oregano. Stir to combine, then simmer for 8 to 10 minutes until mixture is thickened. Remove from heat.
05 - Slice the baguette in half lengthwise. In a mixing bowl, blend softened butter with minced garlic, chopped parsley, and 1/4 teaspoon salt until smooth.
06 - Spread garlic butter evenly over the cut sides of both bread halves. Arrange bread, cut side up, on the prepared baking sheet.
07 - Bake for 5 to 6 minutes until the bread is lightly golden. Remove from oven.
08 - Generously spoon the sloppy joe mixture onto one half of each bread piece. Sprinkle with mozzarella and Parmesan cheese.
09 - Return to the oven for an additional 5 to 6 minutes, or until the cheese is melted and bubbly.
10 - Place the remaining bread halves over the filled portions, press gently, and slice into servings. Serve hot.