If using the grill, preheat the grill, putting all settings on direct heat. Close the grill and let the temperature reach 500-600 degrees. If using the oven, skip this step.
In a mixing bowl, combine the mayo, lime juice, salt, chili powder, and smoked paprika. Mix until combined and taste to make sure you like the flavor. Adjust the seasoning to your taste if necessary.
Brush each piece of corn with the mayo mixture until they're evenly coated. Reserve the leftover mayo for the crema.
If using a grill: place the corn directly onto the grill grates. Grill the corn for about 3 minutes per side, or until the kernels begin to look charred. Turn and repeat. When all sides are charred (about 10-12 minutes,) remove from the grill onto a plate.
If using the oven: place the corn onto a large sheet pan. Broil the corn for about 3 minutes per side, or until the kernels begin to look toasted and bright yellow. Remove the pan from the oven, turn the corn, and repeat. When all sides are charred (about 10-12 minutes,) remove from the grill onto a plate.
Let the corn cool. Preheat the oven to 350 degrees. As the corn cools, add the sour cream to the leftover mayo and mix until combined. Feel free to add more lime juice to thin out the crema, but it’s not necessary. During this time, you can shred the cheese and prep the nacho ingredients.
One by one, stabilize each piece of corn on the flattest end. Hold it vertically and use a sharp knife to slice the kernels off of the cob. Repeat with all of the corn.
On a large sheet pan or in a large skillet, layer chips (try to not overlap when possible) and top with both shredded cheeses, corn, and a swirl of crema. Repeat 2 more times. Once the final layer is complete, top with shredded cheeses, corn, a swirl of crema, plus Cotija cheese, and a dusting of paprika and chili powder.
Bake for 20 minutes until the cheese is melted. Remove the nachos from the oven and top with cilantro, one more crema drizzle, and extra lime juice. Enjoy!