Mix ground turkey, seasoned bread crumbs, onion, eggs, mustard, ketchup, garlic powder, paprika, kosher salt, and pepper in a large bowl.
Form the turkey mixture into 8 patties by shaping into a patty and then making a small indentation in the center of each patty.
Grill: If grilling, freeze the patties on a piece of waxed paper for about 15-20 minutes so that they can hold their shape better.
Skillet: If cooking the burgers on the stove, heat a large skillet. Add 1-2 tablespoons of oil and swirl to coat or grease with a nonstick cooking spray.
Cook the patties on the grill or in a skillet until they reach an internal temperature of 165F, flipping halfway through cooking.
Notes
Ground turkey: I use 93% lean turkey when I make turkey burgers. I don't recommend using 99% lean because it tends to dry out.
Bread crumbs: You have several options when it comes to bread crumbs. I've used both panko and regular bread crumbs, and both types work well. If you can't find seasoned bread crumbs, you can use plain and increase the amount of seasonings in the burger.
Dijon mustard: I've used stone-ground Dijon and regular Dijon mustard. Yellow mustard or spicy brown mustard could also work.
Spices: Feel free to play around with the spices. You can increase the amounts, or use other seasonings, like onion powder.
Kosher salt: If using table salt, only use 1/4 teaspoon.