Prepare Salmon: Slice the salmon fillet into thin, even strips.
Marinade Mixture: In a bowl, combine soy sauce, brown sugar, maple syrup, apple cider vinegar, liquid smoke (if using), garlic powder, black pepper, and cayenne pepper.
Marinate Salmon: Place the salmon strips in the marinade, ensuring they are fully submerged. Marinate in the refrigerator for at least 2 hours, preferably overnight.
Oven Preparation: Preheat your oven to 150°F (65°C). Line a baking sheet with parchment paper and place a wire rack on top.
Arrange Salmon: Lay the marinated salmon strips on the wire rack, ensuring they don't overlap.
Bake: Bake for 3 to 4 hours, or until the jerky is dry and firm yet still slightly pliable.
Cool and Store: Allow the salmon jerky to cool completely before storing in an airtight container.