In a medium saucepan, bring 2 cups of water to a boil. Add the rice, reduce heat to low, cover, and simmer for 15 minutes or until rice is tender and water is absorbed.
Remove the rice from heat and fluff with a fork. Stir in lime juice and 1/4 cup chopped cilantro. Set aside.
In a small bowl, combine chili powder, ground cumin, garlic powder, smoked paprika, salt, and black pepper.
Pat the chicken breasts dry and rub both sides evenly with the spice mixture.
Heat olive oil in a large skillet over medium-high heat. Add the chicken breasts and cook for 6-7 minutes per side or until the internal temperature reaches 165°F (75°C) and the chicken is cooked through.
Remove the chicken from the skillet and let rest for 5 minutes before slicing into strips.
In a medium bowl, combine diced tomato, red onion, 1/4 cup chopped cilantro, and 1 tablespoon lime juice to make the fresh salsa.
To assemble the burrito bowls, divide the cilantro lime rice evenly among four bowls.
Top each bowl with sliced chicken, black beans, corn, fresh salsa, sliced avocado, and shredded cheddar cheese.
Serve immediately with a dollop of sour cream if desired.