Preheat oven to 400 degrees.
In medium bowl, crumble ground beef (or ground turkey). Set aside.
In a measuring cup or small bowl, add egg, salt, black pepper, garlic powder, onion powder, Liquid Smoke, Worcestershire sauce (optional). Combine thoroughly with a fork.
Pour liquid mixture over ground beef. Mix thoroughly with fingers or use a large spoon.
Crumble 2 slices of toasted bread over meat mixture. Add diced onion. Combine thoroughly with fingers or a large spoon.
For easy clean up, line a 9x9 (or larger) baking pan with parchment paper or foil with shiny side down.
Form a meatball with three tablespoons of mixture. They will shrink while baking. Make larger size if preferred.
Arrange on lined baking sheet about 1/2" apart. Bake 15-20 minutes or until browned inside and outside. Drain on paper towels.
Repeat until all beef mixture is baked.
Serve hot.