In a large mixing bowl, use a stand or hand-held mixer to beat together the lime gelatin powder and softened cream cheese until well blended and creamy. This helps prevent lumps and ensures a uniform texture.

With the mixer running on the lowest speed, slowly add the boiling water to the cream cheese and gelatin mixture. Start with a small amount so the mixture incorporates smoothly. Once it begins to loosen up, add the rest of the water all at once. Continue to mix until the mixture is completely smooth, with no lumps of cream cheese remaining.

Pour the cream cheese and lime gelatin mixture from Step 2 into a decorative mold or serving dish. Place it in the refrigerator and let it chill until partially set, about 2 hours. Be sure to check periodically; the mixture should be thickened but not fully firm.

Once the mixture is partially set, remove it from the refrigerator. Gently stir in the drained crushed pineapple, chopped pecan pieces, finely diced celery, and miniature marshmallows. Stir well to distribute the ingredients evenly. This step adds both flavor and texture—I like to mix everything thoroughly so you get a bit of each ingredient in every bite.

Return the dish to the refrigerator and chill until completely set, about 4 more hours. After 1 hour, check to make sure the marshmallows haven’t floated to the top—if they have, gently stir them back in. Once fully set, cut the salad into squares for serving.