We like pasta salads. This is a good one. The pineapple and raisins add some exciting taste to the dish. This is always a hit at pot luck dinners. If you make this once, you will be making it again and again.
Make Dressing: Whisk 1-1/2 cups milk, 1 cup mayonnaise, 1 tablespoon brown sugar, 1/2 teaspoon salt, and 2 teaspoons pepper in bowl. **(Low-fat milk or mayonnaise will make the dressing too thin.)
Cook Pasta: Bring 4 quarts water to boil in large pot. Add 1 tablespoon salt and pasta and cook until very soft, about 15 minutes. Drain pasta and return to pot. Add vinegar and toss until absorbed. Transfer to bowl. Cool pasta 10 minutes, then stir in dressing until pasta is well coated. Cool completely.
Make Salad: Add scallions, carrots, celery, pineapple, raisins, 1/2 cup milk, and 1 cup mayonnaise to pot with pasta mixture and stir to combine. Adjust Seasoning salt and pepper to taste. Transfer to serving bowl and refrigerate, covered. for at least 1 hour or up to 2 days. Serve.