Place a grill pan on the grill and preheat to medium heat, approximately 450ºF.
In a large bowl, toss the cauliflower florets with oil, salt, chilli powder, black pepper, and garlic powder.
Transfer cauliflower florets to the hot grill pan. Allow to cook, stirring cauliflower florets occasionally, until evenly browned and slightly tender, approximately 10-15 minutes.
Meanwhile, combine all of the ingredients for the sauce in a small bowl.
Transfer the cauliflower to a serving plate and drizzle with the crema sauce. Sprinkle with crumbled cotija, and garnish with cilantro and lime wedges, if desired.