- Preheat your oven to 375°F (190°C). 
- In a large bowl, combine the shredded chicken, cooked rice, black beans, corn, salsa, cumin, chili powder, garlic powder, onion powder, salt, and pepper. Mix well until all ingredients are evenly incorporated. 
- Lay out a tortilla on a clean surface. Spoon about 1/2 cup of the chicken mixture onto the center of the tortilla. Sprinkle with a little cheese, then fold in the sides and roll it up tightly. Repeat with the remaining tortillas and filling. 
- Place the rolled burritos seam-side down in a greased 9x13 inch baking dish. 
- Pour any remaining salsa over the top of the burritos, then spread the sour cream evenly over the salsa. 
- Sprinkle the remaining cheese on top of the burritos. 
- Cover the baking dish with aluminum foil and bake for 20 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and golden. 
- Remove from the oven and let cool for a few minutes. Garnish with chopped cilantro if desired before serving.