In a small saucepan bring cola and brown sugar to a boil over medium-high heat and boil, stirring occasionally until sugar is dissolved and liquid reduces to about 1 cup, about 10 minutes. Set aside to cool slightly.
In a small bowl add cooled soda, tomato sauce, worcestershire sauce, tomato paste, vinegar, mustard, garlic powder, salt and pepper and whisk until blended. Set aside.
In a large skillet heat olive oil over medium-high heat. Add peppers and onions and cook until slightly tender, about 5 minutes. Add in beef and cook thoroughly. Drain any excess grease.
Stir in sauce and continue to cook over medium-high heat, stirring occasionally until sauce thickens, about 12 minutes.
Remove from heat and serve on rolls.
Try serving the sauce over pasta like elbow noodles or orrechiette. These are also great served on garlic toast instead of rolls.