In a large skillet over medium heat, cook the ground beef until browned. Drain excess fat if needed.
Add brown sugar, soy sauce, sesame oil, red pepper flakes, ground ginger, and garlic. Stir well to combine.
Simmer for 2–3 minutes to let the flavors meld together.
Serve the beef mixture over hot cooked rice.
Top with chopped green onions and sesame seeds, if desired.