Chop half of the nuts of your choice and leave the other half for garnish.
Place the crushed pineapples in a bowl and add the pistachio Jell-O instant pudding mix. Mix until well combined.
Add the miniature marshmallows and chopped nuts. Mix with a spatula until well combined.
Now add the Cool Whip to the pudding mixture and gently fold it into the mixture with a spatula.