Preheat the oven to 400°F. Line a baking sheet with parchment paper or lightly grease it.
In a small bowl, whisk together olive oil, lime juice, minced garlic, cumin, chili powder, salt, and pepper.
Place the salmon fillets on the prepared baking sheet and brush the mixture generously over the top of each fillet.
Bake the salmon in the preheated oven for 12-15 minutes, or until the salmon flakes easily with a fork.
While the salmon is baking, prepare the avocado salsa by combining diced avocado, tomato, red onion, cilantro, lime juice, and salt in a medium bowl. Gently mix until well combined.
Once the salmon is done, remove it from the oven and let it rest for a few minutes. Serve the salmon topped with the avocado salsa.