Thaw the frozen corn completely and press it between layers of paper towels until it is as dry as possible. Spread it on a sheet pan lined with paper towels and let it sit for at least 5 minutes. Wet corn will steam instead of char.

Heat a large cast iron skillet over high heat until very hot. Add the butter and let it melt, then add the corn in a single layer. Do not stir. Let it sit undisturbed for 2-3 minutes until charred spots appear on the bottom.

Stir the corn once, let it sit another 1-2 minutes for more char, then remove from heat. Season with kosher salt and let it cool slightly while you prepare the creamy base.

In a large bowl, whisk together the mayonnaise, sour cream, lime juice, and garlic powder until smooth. Taste and adjust lime or salt as needed.

Add the warm charred corn to the bowl. Fold in the crumbled cotija, diced jalapeño, cilantro, chili powder, and smoked paprika. Stir until everything is evenly combined.

Let the dip rest for 10 minutes before serving. This resting time allows the mayo and cotija to meld together and the dip to thicken to the right consistency — it should hold shape on a chip.

Transfer to a serving bowl. Top with extra crumbled cotija, a sprinkle of Tajín, and fresh cilantro. Serve immediately with sturdy tortilla chips.