Preheat oven to 400 degrees. Line a baking sheet with parchment paper and lightly grease with oil.
Make the barbecue sauce (or use store-bought for a quicker dinner) by adding all the ingredients to a small pot. Bring to a simmer over medium heat, stirring often. Simmer until the sauce is reduced by half, about 15 minutes.
While the bbq sauce is simmering make the salsa. Combine the onion and lime juice in a bowl while you prep the rest of the ingredients (this takes the bite out of the onion.) Then add the rest of the ingredients into the bowl and stir. Set aside.
Place the salmon fillets on the prepared baking sheet and sprinkle lightly with salt. Brush with bbqsauce on the top and sides generously.
Bake for 6-8 minutes, or until almost done.
Remove the pan from the oven and brush the fillets again with bbq sauce.
Broil for 2-3 minutes so the barbecue sauce gets bubbly and sticky.
Transfer the salmon to plates and top with pineapple-mango salsa and chopped cilantro.