In a large bowl, combine the drained, flaked salmon.
Add the diced onion and chopped parsley, if using.
Crack the eggs into the bowl.
Add the breadcrumbs, Dijon mustard, garlic powder, onion powder, salt, and black pepper.
Stir until all ingredients are evenly mixed.
Shape the mixture into 6 even patties and place them on a shallow plate.
Heat the oil in a skillet over medium heat.
Once the oil is hot, place the patties in the skillet without overcrowding.
Cook for about 4–5 minutes on the first side until golden brown.
Carefully flip each patty and cook another 4–5 minutes until both sides are crisp and the center is heated through.
Transfer cooked patties to a plate lined with a paper towel to drain excess oil.
Serve warm with lemon wedges or your favorite sauce.