01 - Whisk together olive oil, chili powder, smoked paprika, garlic powder, cumin, salt, black pepper, and lime juice in a bowl. Add chicken breasts and coat evenly. Let marinate for 10-15 minutes.
02 - Preheat grill or grill pan over medium-high heat. Grill chicken for 6-7 minutes per side until cooked through and juices run clear. Rest for 5 minutes, then slice into strips.
03 - Melt butter in a skillet over medium-high heat. Add corn kernels, chili powder, and salt. Cook, stirring occasionally, until corn is lightly charred, about 5-7 minutes.
04 - Whisk together sour cream, mayonnaise, lime juice, garlic powder, and salt in a small bowl until smooth and well combined.
05 - Divide cooked rice among 4 bowls. Top each bowl with sliced chicken, charred corn, cotija cheese, cilantro, green onions, jalapeño, and avocado. Drizzle with crema and serve with lime wedges.