Bring a large pot of salted water to a boil. Add linguine and cook according to package instructions until al dente. Drain and set aside.
In a small bowl, combine smoked paprika, garlic powder, onion powder, ground cumin, chili powder, salt, and black pepper.
Heat olive oil in a large skillet over medium-high heat. Add chicken pieces and sprinkle the spice mixture over them. Cook for 6-8 minutes, stirring occasionally, until chicken is cooked through and lightly browned. Remove chicken from skillet and set aside.
Reduce heat to medium and add butter to the same skillet. Once melted, add minced garlic and cook for 1-2 minutes until fragrant, stirring frequently to avoid burning.
Stir in chopped parsley, crushed red pepper flakes, and lemon juice. Cook for another 1 minute to combine flavors.
Return the cooked chicken to the skillet and toss to coat with the cowboy butter sauce.
Add the cooked linguine to the skillet and toss everything together until the pasta is evenly coated with the sauce and chicken is well distributed.
Remove from heat and sprinkle grated Parmesan cheese over the top. Toss gently to combine.
Serve immediately, garnished with additional parsley or Parmesan if desired.