Drain the pineapple, saving the juice. Put it into a large bowl and add the dry pudding mix. Stir together.
Mix the cottage cheese (if using) into the mixture then fold in the cool whip.
Add the mini marshmallows and a couple tablespoons of the pineapple juice (add more juice to desired consistency) Stir untill combined.
Chill for 1 hour before serving. Sprinkle chopped pecans onto each serving or you can add them into the salad.
If you don't want to use cool whip. You can whip up 1 1/2 cups of heaving whipping cream & 1/2 cup powdered sugar in place of the cool whip.
Sweet shredded coconut is also yummy in this salad and the cottage cheese is optional. I like the added texture and tang but it is very good without too!