Season the shrimp with chili powder, cumin, garlic powder, salt, and pepper. Heat olive oil in a skillet over medium-high heat. Cook shrimp for about 2-3 minutes on each side until opaque.
In a bowl, combine diced mangoes, red onion, cilantro, lime juice, and jalapeño (if using) to create the mango salsa.
To assemble the bowls: Start with a base of rice or quinoa. Top with cooked shrimp, avocado slices, and mango salsa.
Drizzle optional dressing over the top and add any desired toppings.