Preheat your oven to 400°F. Mix olive oil, garlic powder, onion powder, salt, and black pepper in a bowl. Coat chicken breasts with the mixture and place on a lined baking sheet.
Bake the chicken for 20-25 minutes until it reaches an internal temperature of 165°F. Let it rest for 5 minutes, then shred into bite-sized pieces.
Divide cooked brown rice among four bowls. Top each bowl with shredded buffalo chicken.
Add halved cherry tomatoes, shredded lettuce, and sprinkle shredded cheddar cheese on top. Drizzle with ranch dressing if desired and garnish with sliced green onions.