In a skillet over medium heat, cook the ground beef with the onion, bell pepper, chili powder, garlic powder and cumin until the beef is cooked through. Season with salt and pepper to taste.
Brush one side of each tortilla with melted butter. Place one tortilla butter-side down on a plate and spread the salsa verde evenly over the top. Top with the cooked beef mixture then sprinkle with cheese.
Top with the remaining tortilla butter-side up. Heat a large skillet over medium heat and cook the quesadilla for about 2 minutes per side or until golden brown and cheese is melted.