Place macaroni in medium saucepan and add just enough cold water to cover. Add a pinch of salt and bring water to a boil over high heat. Continue to cook, stirring until water has been almost completely absorbed, about 6 minutes.
Immediately add evaporated milk and bring to a boil. Add cheese. Reduce heat to low and cook, stirring continuously until cheese is melted and liquid has reduced to a creamy sauce, about 2 minutes longer. Season to taste with more salt.
Deep fry popcorn chicken for 2-5 minutes, to internal temperature of 165F. Immediately toss cooked popcorn chicken in Ranch seasoning, if desired.
Place macaroni & cheese into bowl and top with popcorn chicken. Drizzle with Buffalo sauce.