Prepare the salmon by patting it dry with paper towels to remove excess moisture. This helps the marinade stick better.
Create the marinade by whisking together olive oil, soy sauce, honey or maple syrup, Dijon mustard, garlic powder, and black pepper in a bowl until well combined.
Marinate the salmon by placing it in a zip-top bag and pouring the marinade over it. Seal the bag tightly after squeezing out the air, then refrigerate.
Let the salmon marinate. For best results, marinate at room temperature for 30 minutes or in the refrigerator for up to 1 hour.
Cook the salmon to perfection. If using an oven, bake at 400°F until it reaches the desired doneness. For grilling, cook on a hot grill until the salmon is cooked through and rests easily.