In a small bowl, combine the chili powder, smoked paprika, cayenne pepper, and a pinch of salt.
Heat the olive oil in a large skillet over medium-high heat.
Add the chopped onion and cook for about 5 minutes until softened.
Stir in the corn kernels, garlic, 1 teaspoon of the spice blend, and season with salt and black pepper.
Cook for another 5 minutes until the corn is tender and lightly caramelized.
Reduce the heat to low and stir in the softened cream cheese until completely melted.
Mix in the sour cream until smooth and creamy. Add a splash of milk if a thinner consistency is preferred.
In another small skillet, melt the butter until lightly golden.
Stir in 3 teaspoons of the spice blend along with a pinch of chili flakes and cook for 1 minute.
In a separate bowl, combine the mayonnaise (or Greek yogurt) with fresh lime juice and a pinch of salt.
Transfer the Mexican Street Corn Dip to a serving bowl.
Top with the grilled corn kernels.
Drizzle the lime mayo and spicy butter over the dip.
Finish with crumbled cotija cheese and fresh cilantro.
Serve warm with tortilla chips, pita chips, crackers, or fresh vegetables.