In a small bowl, whisk together the sour cream, mayonnaise, Parmesan cheese, lime juice, chili powder, garlic powder, cumin and ancho chile powder.
Rub the corn with olive oil, then sprinkle with salt and pepper
Clean, oil and preheat the grill to medium- high. Place the corn on the grill, close the lid if using one and cook, turning frequently until lightly charred and softened, about 10 minutes.
Remove the corn from the grill and let cool slightly. Generously brush with the sour cream mixture, sprinkle with more Parmesan, and serve immediately.
Notes
To turn this into a skillet recipe: Cut the corn off the cob into a bowl. Slowly stir in the sour cream mixture to your desired taste and consistency. Serve as a salad or dip.