Preheat oven to 375 degrees.
Prepare your glaze. Combine mayonnaise, yellow mustard, dijon mustard, brown sugar, garlic powder, onion powder, and a pinch of salt and black pepper.
Whisk ingredients until well combined, and creamy.
Place salmon on a large piece of foil. Make sure to check for any bones.
Top the salmon so its completely covered with mustard glaze.
Bring foil together at sides and top. Crunch together so there are no areas for heat to sneak out.
Bake in preheated oven for 15-20 minutes. Fish is done when it flakes off easily with a fork.
Sprinkle and garnish with some fresh parsley for looks and flavor! (optional)
Enjoy!