Preheat the oven to 350º F and lightly grease a 9x13-inch baking dish with non-stick spray.
In a medium bowl, whisk together the condensed cream of mushroom soup and whole milk, then stir in the freshly chopped parsley. Set this mixture aside.
In a separate large bowl, combine the ground beef, crushed saltines, milk, Italian seasoning, garlic powder, onion powder, and cayenne. Season generously with salt and pepper.
Using your hands or two forks, mix the ingredients until just combined. Gently shape the mixture into even-sized patties.
Place 1 cup of all-purpose flour (or more, if needed) in a shallow dish and dredge the patties in the flour.
Heat a large skillet over medium-high heat. Once the skillet is very hot, sear the patties on both sides until golden brown. You may need to work in batches. The patties will still be undercooked inside.
Transfer the browned patties to the prepared baking dish, then evenly pour the gravy over them. Cover the dish with aluminum foil.
Place the baking dish in the oven and bake for 30-40 minutes, or until the patties are cooked through.