Cook the pasta: Cook the rotini pasta according to the package instructions. Drain and rinse with cold water to cool.
- Prepare the vegetables: Dice the cucumbers, red bell pepper, and finely chop the red onion. Slice the black olives if using.
- Make the dressing: In a large bowl, whisk together the mayonnaise, vinegar, Dijon mustard, garlic powder, onion powder, salt, and pepper. Adjust seasoning to taste.
- Combine ingredients: Add the cooled pasta, diced vegetables, and shredded cheddar cheese to the bowl. Toss gently to combine.
- Add the dressing: Pour the dressing over the pasta mixture and stir until everything is well coated. Sprinkle in the black olives if desired.
- Chill and serve: Refrigerate the pasta salad for at least 1 hour before serving to let the flavors meld. Serve cold and enjoy!