Preheat oven to 425°F. Line a large rimmed baking sheet with parchment paper. Set aside.

Heat a large skillet over medium-high heat. Add the ground beef, and cook until no longer pink, about 4 to 5 minutes. Drain the excess grease from the skillet.

Add the butter, onions, salt, and pepper to the skillet and saute for 2 to 3 minutes or until the onions are soft and translucent.

Stir in the brown sugar, yellow mustard, ketchup, Worcestershire sauce, garlic powder, onion powder, and Italian seasoning. Cook for 3 to 4 minutes, or until the sauce has thickened.

While the sauce is cooking, place the frozen Texas Toast onto the prepared baking sheet. Bake in preheated oven for 6 minutes.

Remove the baking sheet from the oven and evenly distribute the sloppy Joe mixture on top of the Texas Toast.

Top each toast with shredded mozzarella cheese, about 1/8 cup each. Place the baking sheet back into the oven for 3 to 4 minutes or until the cheese has melted.

Garnish with chopped parsley and serve immediately.