Drain the fruit well: Press the crushed pineapple in a fine-mesh strainer to remove excess juice.
Do the same with the maraschino cherries, then chop them. Extra liquid can make the fluff runny.
Whisk the base: In a large bowl, whisk together the instant vanilla pudding mix, sour cream, and vanilla extract until smooth. The mixture will be thick.
Fold in the whipped topping: Add the whipped topping and gently fold until fully combined and fluffy.
Don’t overmix—keep it airy.
Add the fruit: Fold in the drained pineapple and chopped cherries until evenly distributed.
Stir in mix-ins: Add mini marshmallows, coconut, and nuts if using. Sprinkle in a pinch of salt. Fold gently to avoid deflating the mixture.
Chill: Cover the bowl and refrigerate for at least 2 hours, or up to overnight.
This helps the flavors meld and the marshmallows soften slightly.
Garnish and serve: Give it a gentle stir before serving. Top with a few whole cherries, extra coconut, or chopped nuts for a pretty finish.