Sauté corn: Add butter to a large skillet over medium heat. Add onion, corn and chipotle peppers and stir. Turn heat to high, cover with lid and sauté, stirring occasionally, until corn is charred and tender, about 4-5 minutes. Remove from heat and transfer to a plate to cool completely.
Cook pasta according to package instructions, in salted boiling water. Drain and rinse with cold water to cool it off.
Mix sauce ingredients in a bowl: mayo, sour cream, tajin, lime and milk.
Combine: Add pasta to a large mixing bowl. Add cooled corn and stir in sauce. Top with cotija cheese and cilantro and enjoy immediately.
