In a small bowl whisk together the garlic, onion and chili powders with the paprika, salt and white pepper. Reserve 2 teaspoons and set aside.
If chicken breasts are large, split by cutting each horizontally to butterfly and create two pieces. Season both sides of each chicken piece in a large bowl, pressing spice mixture with your hands to adhere. Reserve any leftover spice mix for the sauce.
In a large skillet over medium heat add olive oil and sauté chicken several minutes each side to brown. Cook in batches to not over crowd if necessary.
Remove chicken from the pan, cover and keep it warm.
In a large pot of boiling salted water, cook pasta according to package instructions and drain. In a bowl, toss pasta with some olive oil and half of the chopped parsley. Set aside and keep covered.
Add the reserved spice mix to the sauté pan and cook for a minute. Add the cream, stirring to mix and bring to a boil. Turn heat to low and cook to reduce by half and sauce coats the back of a spoon, about 10-15 minutes.
Serve chicken over pasta dressed with olive oil an seasoned with salt and pepper. Pour sauce over all and sprinkle chopped parsley over top.
Feel free to substitute Half and Half cream for heavy.