Cook the pasta according to the package directions. Drain then rinse under cold water until cool. Set the pasta aside.
Preheat the grill over medium high heat and grease the grates with some high heat cooking oil. Add the corn to the grill and cook for about 11-12 minutes, rotating about every 3 minutes, until tender and charred all around.
In the meantime, rub the olive oil onto both sides of the chicken breast. Combine the onion powder, garlic powder, smoked paprika, chili powder, salt, and pepper in a small bowl. Sprinkle the spice mixture onto both sides of the chicken. Add the chicken to the grill and cook for about 2-3 minutes on each side until fully cooked. Remove the chicken and corn from the grill when done and set aside to cool slightly. When the corn and chicken have cooled, slice the corn kernels off the cob. Dice the chicken into pieces.
Add the pasta, corn, chicken, avocado, jalapeño, cilantro, and cotija cheese into a large bowl. Drizzle the dressing over top. Gently toss everything together until evenly combined. Taste for seasoning and add more salt or pepper if necessary. Top the pasta salad with more crumbled cotija, a sprinkle of tajin, cilantro leaves, and jalapeño slices. Enjoy!