Cook the spaghetti according to the package directions; add the zoodles in the last 5 minutes of cooking. Drain.
Combine the chicken cutlets and olive oil in a mixing bowl. Add in the cajun seasoning, chili powder, salt, and pepper; toss together and set aside.
Melt 2 tablespoons butter in a 12-inch cast iron skillet (or a pan) set over medium-high heat.
Add the chicken cutlets to the skillet and cook for 5 minutes per side, or until done. Chicken is cooked through when internal temperature registers at 165˚F.
Remove chicken from skillet and set aside.
Return skillet to the burner and add in the remaining butter; stir in the garlic and cook for 15 seconds.
Whisk in the chicken broth and cook for 1 minute.
Whisk in the heavy cream and bring sauce to a simmer; continue to simmer for 5 minutes.
Whisk in the parmesan cheese.
Add the drained zucchini and pasta to the sauce; cook for 2 minutes.
Remove from heat.
Slice the chicken cutlets.
Transfer pasta and chicken to a serving plate.
Garnish with parsley and serve.