Mix the Spices: In a small bowl, combine the chili powder, paprika, cayenne, and salt. Set aside.
Cook the Onion and Corn: Heat the olive oil in a skillet over medium-high heat. Add the chopped onion and sauté for about 5 minutes until softened. Stir in the corn, garlic, 1 teaspoon of the spice mix, and season with salt and pepper. Cook for another 5 minutes until the corn is tender.
Add the Creamy Ingredients: Lower the heat to low, then mix in the cream cheese, letting it melt into a creamy consistency. Stir in the sour cream and shredded cheddar until everything is heated through. If the dip is too thick, you can add a little milk to thin it out.
Prepare the Spicy Butter: In a separate skillet, melt the butter over medium heat until it turns golden. Stir in 3 teaspoons of the spice mix, a pinch of chili flakes, and a bit of salt. Cook for one more minute, then remove from the heat.
Mix the Mayo: In a small bowl, stir together the mayo and lemon juice.
Assemble the Dip: Transfer the warm dip to a serving bowl. Top with the grilled corn kernels, then drizzle the mayo mixture and spicy butter over the top. Finish by sprinkling on crumbled cheese and fresh cilantro.
Serve with plenty of chips for dipping and enjoy!