Melt butter in a cast iron skillet over medium heat. Add garlic and onion and cook about 2-3 minutes.
Add corn kernels and cook for 15-20 minutes, stirring occasionally to char evenly throughout without burning.
While the corn is cooking, add lime juice, sour cream, mayo, Cotija cheese, cilantro, chili powder, garlic salt, and paprika to a large bowl and mix well until creamy.
When corn is done cooking, allow to cool slightly before adding to dressing bowl. Stir well.
Garnish with chili powder, cilantro, Cotija cheese crumbles, and green onion.
