In a small bowl, combine sour cream, olive oil, salt, pepper, garlic powder, onion powder, and ground cumin. Whisk together until smooth and creamy, then set aside.

In a large mixing bowl, add sweet corn, black beans, Rotel tomatoes, diced bell pepper, and shredded cheddar cheese. Mix everything evenly.

Pour the dressing over the salad mixture. Using a spatula, gently stir until everything is evenly coated.

Add Fritos just before serving and carefully fold them in.

Garnish if desired and serve chilled or at room temperature.