Preheat oven to 400°F.
Line baking sheet with parchment paper.
Pat salmon fillets completely dry.
Brush salmon with olive oil evenly.
Season with salt, pepper, and garlic powder.
Place salmon on prepared baking sheet.
Bake for 12-15 minutes until flaky.
Meanwhile, mash avocados in mixing bowl.
Add cotija cheese to mashed avocados.
Stir in lime juice and cilantro.
Add minced jalapeño for heat.
Mix all ingredients until well combined.
Remove salmon from oven when done.
Top each fillet with avocado mixture.
Serve immediately while salmon is warm.