In a small bowl, stir together 1/2 cup mayonnaise, 1 small minced garlic clove, 2 tablespoons diced pickled jalapeno peppers, and 1 tablespoon pickled jalapeno juice. Cover and refrigerate until needed.

Drain the 15-ounce pouched or canned salmon. Remove and discard any large bones or skin, then flake the salmon with a fork into a medium bowl.

Add 1/2 cup Panko crumbs, 1 large egg, 1/4 cup mayonnaise, 2 teaspoons Cajun seasoning, 1/2 red bell pepper (finely diced), 1/3 cup finely diced onion, 1/2 teaspoon garlic powder, and 1/2 teaspoon pepper to the flaked salmon. Stir gently until the mixture is evenly combined and holds together.

Shape the mixture into 6 to 8 patties of even size. Place the patties in a single layer on a plate or tray and freeze for 20 minutes to firm them (this helps them hold together while cooking).

Heat 1 to 2 tablespoons vegetable oil in a large nonstick skillet over medium heat until the oil shimmers. Add patties in a single layer (work in batches if the skillet is crowded).

Cook the patties about 3 minutes per side, or until each side is golden brown and the patties are heated through. Flip carefully with a spatula; adjust heat as needed to prevent burning.

Transfer cooked patties to a paper-towel–lined plate to drain briefly. Serve the salmon cakes with the refrigerated jalapeno mayonnaise.