Step 1: Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions until al dente.
Step 2: Drain the pasta in a colander and immediately rinse with cold water until completely cool. Shake well to remove excess water.
Step 3: In a large bowl, whisk together the mayonnaise, garlic powder, salt, and pepper until smooth.
Step 4: Add the cooled pasta, chopped celery, and red onion to the bowl with the dressing.
Step 5: Fold all ingredients together gently until evenly coated in the creamy dressing.
Step 6: Cover the bowl and refrigerate for at least 1 hour to let flavors meld.
Step 7: Give the salad a final stir before serving and adjust seasoning if needed.
Notes
For extra flavor, add a tablespoon of white vinegar or a squeeze of fresh lemon juice to the dressing. Optional mix-ins include peas, shredded carrots, or diced ham. If the salad absorbs too much dressing while chilling, stir in a little milk or extra mayonnaise to loosen.