Step 1: Cook the pasta: Bring a large pot of salted water to a boil. Cook pasta according to package directions until al dente. Drain and transfer to a large mixing bowl.
Step 2: Char the corn: Heat a cast iron skillet over medium-high heat. Melt butter, then add corn kernels and cook until charred in spots, about 5 to 8 minutes. Sprinkle with salt and transfer to the bowl with the pasta. Let cool slightly.
Step 3: Make the dressing: In a separate bowl, whisk together mayonnaise, Mexican crema, lime juice, sugar, chili powder, garlic powder, salt, and black pepper until smooth.
Step 4: Add the mix-ins: Add onion, cotija cheese, cilantro, and jalapeño to the pasta and corn mixture.
Step 5: Combine everything: Pour dressing over the pasta mixture and stir until everything is evenly coated.
Step 6: Finish and serve: Sprinkle extra chili powder or Tajin on top before serving. Enjoy warm or cold.