Preheat your oven to 400°F. Line a baking sheet with parchment paper.
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 marinade over the top of each fillet. Sprinkle chopped cilantro on top.
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, lime juice, salt, and pepper in a bowl. Gently mix until combined.
Once the salmon is done, remove it from the oven and let it rest for a few minutes. Serve topped with the avocado salsa.