Rinse rice under cold water until clear. In a medium saucepan, combine rice, water, and a pinch of salt. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes. Remove from heat and let sit covered for 5 minutes.
In a large mixing bowl, toss chicken cubes with olive oil, chili powder, cumin, garlic powder, smoked paprika, salt, and pepper.
Heat a large cast-iron skillet over medium-high heat. Add chicken in a single layer and sear for 8-10 minutes, turning occasionally, until the internal temperature reaches 165°F (74°C). Remove chicken and set aside.
Wipe the skillet and return to high heat. Add corn kernels and cook undisturbed for 3-5 minutes until deeply charred. Remove from heat.
In a small bowl, whisk mayonnaise, sour cream, 1 tablespoon lime juice, and cotija cheese. Fold this mixture into the charred corn.
Fluff the rice with a fork and stir in the remaining 1 tablespoon lime juice and the chopped cilantro.
Assemble bowls by layering a base of cilantro-lime rice, followed by the spiced chicken, and finishing with a generous portion of the street corn mixture.