Preheat oven to 375°F. Line a large sheet pan with parchment paper.
In a large bowl, combine ¾ cup breadcrumbs, eggs, mayonnaise, green onions, parsley, lemon juice, lemon zest, and 1 teaspoon seafood seasoning.
Add flaked trout to the bowl and gently combine. The mixture should be moist enough to stick to together, but not be sticky. If the mixture is too dry, add more mayonnaise, 1 tablespoon at a time.
In a flat bowl or plate, combine the remaining 1 ¼ cups of breadcrumbs with 2 teaspoons seafood seasoning and 2 tablespoons of olive oil. Set aside.
Scoop the trout mixture with a ¼-cup measuring cup, then gently shape each portion into a patty roughly the size of your palm.
Place the patty in the breadcrumb mixture, turning to coat both sides, and press gently so the crumbs adhere.
While the trout cakes are baking (instructions below), prepare the sauce. Combine all sauce ingredients in a small bowl and refrigerate until ready to use.
Place the breaded trout cakes on the sheet pan with parchment paper. Bake for 15-20 minutes, or until the breadcrumbs are golden brown and the internal temperature reaches at least 160°F. If the cakes are not browned to your liking, you can broil them for 2-3 minutes.
I like to use homemade sourdough breadcrumbs, but store-bought breadcrumbs or panko breadcrumbs work great too.
You'll notice this recipe doesn't have any salt! That's because the trout is already salty, and the seafood seasoning takes care of the rest of the saltiness needed. I like to use Old Bay seasoning.
A bright, citrusy dipping sauce completes the dish with just the right contrast. Don't skip it!
Don’t overmix. Fold trout gently so the cakes stay light and flaky.