Preheat oven to 425 degrees and line a baking sheet with parchment paper.
Brown and crumble ground beef in a large nonstick skillet. When it is about halfway cooked, add onion.Drain off any grease.
Add ketchup, mustard, brown sugar, Worcestershire sauce, garlic powder, chili powder and pepper.Simmer for 3 to 5 minutes.
Place Texas Toast Garlic Bread on prepared baking sheet and place in oven for 5 minutes.
Divide sloppy joe mixture evenly between toast slices. Place a mound of mozzarella cheese on top of each one.Return to oven for 2 to 3 minutes to melt the cheese. Serve.
Notes
To save time, pop the garlic bread in the oven while the sloppy joe mixture is cooking.