Bring a large pot of salted water to a boil. Add cavatappi pasta and cook until al dente, about 8-10 minutes. Drain and rinse under cold water.

In a large mixing bowl, whisk together mayonnaise, sour cream, white vinegar, Dijon mustard, sugar, kosher salt, and black pepper until smooth.

Toss the chilled pasta with a splash of additional vinegar or lemon juice.

Add two-thirds of the dressing to the pasta, folding gently to coat.

Fold in red bell pepper, celery, red onion, and carrots. Stir gently to combine.

Add remaining dressing and adjust seasoning to taste.

Cover and refrigerate for at least 2-4 hours or overnight.

Before serving, stir the salad gently and garnish if desired.