In a large bowl, combine ground beef, sauteed onions, garlic powder, salt, and pepper. Using your hands, mix all ingredients together. Form the seasoned beef into two patties.
Place the beef patties onto the grill grates in your preheated Traeger grill. Smoke the patties at 225°F for 30 minutes.
After 30 minutes, crank the heat up to 400°F, flip the burgers, and continue grilling the burgers for 10 minutes, or until your desired doneness.
Toast your burger bun and serve your Traeger burgers with your favorite burger toppings.