In a medium bowl, whisk together the lemon jello and boiling water until fully dissolved, which should take about 2 minutes. Allow the mixture to cool at room temperature for approximately 20 minutes, stirring occasionally until it's no longer hot.

In a large bowl, use a hand mixer to blend the softened cream cheese and crushed pineapple (with juice) on low speed until smooth and well-combined, which should take about 2-3 minutes.

Pour the cooled lemon jello mixture into the cream cheese and pineapple blend. Start mixing on low speed, gradually increasing to medium speed for about 1-2 minutes until everything is thoroughly incorporated and smooth.

Gently fold in the whipped topping using a spatula or a large spoon until it’s evenly distributed and the entire mixture is light and fluffy.

Transfer the fluffy mixture into a serving bowl, smoothing out the top with a spatula. Cover it with cling wrap to prevent any unwanted odors from the refrigerator. Refrigerate for at least 4 hours.

Before serving, optionally top your chilled Lemon Fluff with additional whipped topping and garnishes like lemon zest or slices of fresh fruit.