Preheat grill or grill pan to medium-high heat.
In a small bowl, combine chili powder, ground cumin, smoked paprika, garlic powder, salt, and black pepper.
Rub olive oil over the chicken breasts, then evenly coat with the spice mixture.
Grill chicken breasts for 6-8 minutes per side or until internal temperature reaches 165°F (74°C). Remove from grill and let rest for 5 minutes, then slice into strips.
While chicken cooks, grill the corn ears, turning occasionally, until charred in spots and tender, about 10 minutes. Remove from grill and let cool slightly.
Cut the kernels off the corn cobs and place in a medium bowl.
In a separate bowl, mix mayonnaise, sour cream, minced garlic, lime juice, and chopped cilantro to make the creamy sauce.
Add half of the creamy sauce and half of the cotija cheese to the corn kernels. Stir to combine.
To assemble each bowl, divide cooked rice evenly among four bowls.
Top rice with grilled chicken slices, street corn mixture, diced red bell pepper, diced red onion, and chopped jalapeño.
Drizzle remaining creamy sauce over the top and sprinkle with remaining cotija cheese.
Garnish with fresh cilantro leaves and lime wedges on the side.
Serve immediately and enjoy your Street Corn Chicken Bowl.