In a medium bowl, whisk together butter, brown sugar, water, soy sauce, garlic, lemon juice, and paprika.
Place salmon, skin-side down on the parchment paper lined baking sheet. Place the asparagus around the salmon or on a separate baking sheet. Brush brown sugar mixture over the the salmon and asparagus.
Sprinkle with salt and pepper. Bake 15-20 minutes.