Empty the dry pistachio pudding mix into a large mixing bowl. Pour in the entire undrained can of crushed pineapple, making sure to scrape out all the sweet pineapple juice. Whisk or stir vigorously for 1 to 2 minutes until the dry pudding powder is completely dissolved into the juice and the mixture begins to visibly thicken and turn a lovely green.

Add the 2 cups of small-curd cottage cheese directly to the thickened green pudding base. Stir thoroughly until the cottage cheese is evenly distributed and fully coated by the pistachio mixture.

Spoon the thawed whipped topping into the bowl. Using a rubber spatula, gently fold the whipped topping into the pudding base. Use a circular motion, cutting down through the center and sweeping up the sides of the bowl, until you have a light, uniform, pastel-green color. Avoid stirring vigorously so you don’t deflate the air.

Add the 2 cups of mini marshmallows and ½ cup of chopped pistachios (or pecans) to the bowl. Carefully fold them in just until they are evenly scattered throughout the fluffy salad.

Cover the mixing bowl tightly with plastic wrap or a lid. Place it in the refrigerator to chill for at least 2 hours. During this time, the instant pudding will set firmly, the marshmallows will soften into pillowy clouds, and the flavors will meld.

Give the salad a very gentle fold just before serving. Transfer to a serving dish and top with a sprinkle of extra chopped nuts and a few bright red maraschino cherries for a beautiful, classic color contrast.