In a mixing bowl, combine ground turkey, breadcrumbs, egg, garlic powder, onion powder, salt, and black pepper. Mix until just combined.

Divide the mixture into 4 equal portions and shape them into patties.

Preheat the grill to medium-high heat and lightly oil the grates.

Place the patties on the grill and cook for about 5-7 minutes on each side, or until the internal temperature reaches 165°F (74°C).

In the last minute of cooking, place a slice of cheese on each patty to melt.

Toast the burger buns on the grill for about 1 minute.

Assemble the burgers by placing a patty on each bun and adding lettuce, tomato, pickles, ketchup, and mustard as desired.