In a medium bowl, mix the mayonnaise, sour cream, lime juice, cotija cheese, cilantro, and cayenne pepper (if using). Set aside to let the flavors meld.
Season the chicken breasts with olive oil, chili powder, garlic powder, cumin, salt, and pepper.
Heat a grill pan or skillet over medium-high heat. Cook the chicken for 6-7 minutes on each side, or until fully cooked and no longer pink in the center. Remove from heat and let rest for 5 minutes before slicing.
In the same pan, add the corn and sauté for 3-4 minutes until heated through and slightly charred.
To assemble the bowls, start with a base of cooked rice, top with sliced chicken, sautéed corn, and a generous dollop of the creamy sauce.
Garnish with additional cilantro and lime wedges if desired.