Bring a large pot of salted water to a boil and add the pasta, cooking according to package directions until al dente. Before draining, reserve 1 cup of the starchy pasta water in a separate container—this will be crucial for adjusting the sauce consistency later. While the pasta cooks, pat the chicken breasts dry with paper towels and flatten them to about 1/2 inch thickness using the palm of your hand or a meat mallet. This ensures even cooking and better seasoning penetration. Generously coat both sides of the flattened chicken with the cajun seasoning, pressing gently so it adheres well.

Heat the olive oil in a large skillet over medium-high heat until shimmering and just beginning to smoke. Carefully place the seasoned chicken strips into the pan and cook undisturbed for 5 minutes, allowing a dark, flavorful crust to form—this is where the 'blackened' character comes from. Flip the chicken and cook the other side for another 5 minutes until golden-brown and cooked through. Transfer the cooked chicken to a clean plate and tent loosely with foil to keep it warm while you build the sauce.

In the same skillet (don't wash it—those browned bits add incredible flavor), reduce the heat to low and add the butter. Once melted, add the freshly minced garlic and cook gently for about 2 minutes, stirring frequently, until fragrant but not browned. I prefer to add garlic at low heat rather than high heat to prevent it from becoming bitter. Pour in the heavy cream and increase heat to medium, simmering for about 5 minutes while stirring occasionally, until the cream begins to thicken slightly.

Remove the skillet from heat and immediately stir in the freshly grated parmesan cheese, the remaining 1 tsp cajun seasoning, and the cracked black pepper. Stir vigorously until the cheese is completely melted and the sauce is smooth and creamy. I find that removing the pan from heat before adding the cheese prevents it from becoming grainy or separating. Add the drained pasta from Step 1 to the sauce and toss gently to coat evenly. If the sauce seems too thick, gradually add the reserved pasta water a splash at a time while tossing, until you reach your desired consistency.

Slice the cooked chicken from Step 2 into bite-sized pieces. Divide the creamy pasta among serving bowls and top each portion with the sliced blackened chicken. Garnish with fresh chopped parsley and serve immediately while still hot.