Remove the chicken from the refrigerator and pound to equal thickness (about 1/2-inch) or slice each chicken breast in half to make two thinly sliced chicken cutlets. Pat the chicken dry with paper towels and then season both sides with garlic powder, onion powder, salt, black pepper, and paprika. Set aside.
Cook the bacon in a large skillet set over medium heat until crisp, about 5 minutes. Once cooked, remove the bacon from the skillet with a slotted spoon and set aside. Reserve approximately 2 tablespoons of rendered bacon grease in the pan.
As the bacon cooks, bring a large pot of salted water to a boil. Once boiling, maintain a simmer so that it's ready to cook the pasta when needed.
Return the skillet to high heat and add the olive oil (to the bacon grease). Once hot, add the chicken and cook for about 4-5 minutes per side or until the internal temperature registers 165 ℉ as measured by a digital meat thermometer. Remove the chicken and set aside.
Start cooking the pasta just after you've flipped the chicken over. Cook the pasta until al dente (about 2 minutes less than the package instructions). Before draining, set aside at least two cups of boiling pasta water. Then drain and set aside.
Return the same pan to medium heat. Melt the butter and add the minced garlic. Cook for about 30 seconds, or until fragrant, then whisk in the all-purpose flour and Cajun seasoning. Cook, whisking continuously for about 1 minute.
Tip: If your skillet has a lot of brown bits stuck to the bottom, add 1-2 tablespoons of reserved pasta water to the skillet and scrape off using a metal spatula. Don't toss the brown bits out! That's all delicious, yummy flavor.
Slowly add the heavy cream, whisking continuously. Continue whisking until fully incorporated and the sauce starts to gently simmer - about 5 minutes. Reduce the heat to prevent the sauce from boiling.
Add the pasta and return the bacon to the skillet, turning to coat in the sauce. Sprinkle with the freshly grated parmesan cheese and gently toss to coat. If the sauce is too thick, slowly add reserved pasta water until the desired consistency is reached.
Serve immediately with sliced green onions if desired.