If necessary, remove salmon skin and debone fillets. Use a sharp knife to cut the salmon into roughly 1-inch cubes.
In a small bowl, mix together the cumin, coriander, smoked paprika, garlic powder, chili powder, and ½ teaspoon salt. Add salmon bites to a large bowl and toss with the spice blend and olive oil.
Turn the oven to broil on HIGH. Add the salmon cubes to a baking sheet with parchment paper. Place the sheet pan in the oven on broil for 5 minutes. Remove and allow to cool slightly.
In a separate medium bowl, combine diced mango, diced red onion, jalapeño, chopped cilantro, lime juice, and salt to taste. Mix well and set aside.
Warm the tortillas either by heating them briefly in a skillet over medium heat or wrapped in tin foil in the oven for 10 minutes.
Assemble the tacos by adding 2-3 salmon cubes to each taco and gently pressing them down to flake slightly. Add a scoop of mango salsa and a slice of avocado. Garnish with fresh lime wedges, a sprinkle of cotija cheese, and more cilantro as desired. Drizzle a small amount of Mexican crema or sour cream overtop the salmon taco.
Serve immediately while the tacos are warm and the flavors are fresh.
Squeeze lime juice over the tacos just before eating for an extra burst of citrus flavor.