Bring a large pot of generously salted water to a rolling boil. Cook 1 lb rotini according to package directions until al dente.
Drain the pasta and rinse briefly under cold water to stop cooking and cool it down. Shake off excess water and set aside.
Pat 1½ lbs chicken breast dry. Season both sides with 1 tablespoon olive oil, 1 teaspoon garlic powder, and salt and pepper.
Heat a skillet over medium-high heat and cook the chicken for 6 to 7 minutes per side, until internal temperature reaches 165°F (74°C). Let it rest for 5 minutes before cubing.
Cook 6 slices of bacon in a skillet over medium heat until crisp, about 6 to 8 minutes, flipping once. Drain on paper towels and crumble.
Halve the cherry tomatoes, dice the cucumber and bell pepper, finely dice the red onion, and chop the parsley.
In a small bowl, whisk together 1 cup mayonnaise, ¼ cup sour cream, 2 tablespoons red wine vinegar, 1 tablespoon Dijon mustard, 1 teaspoon Italian seasoning, minced garlic, and 1 teaspoon honey until smooth.
In a large bowl, combine cooled pasta, cubed chicken, tomatoes, cucumber, bell pepper, red onion, cheddar, and half of the bacon. Pour dressing over and toss to coat evenly.
Sprinkle remaining bacon and parsley on top. Cover and refrigerate for at least 30 minutes before serving. Toss gently before serving.