Add the sweetened condensed milk and lemon juice to a large bowl. Use a handheld electric mixer to beat together until light and fluffy, about 2 minutes. Stir in the pineapple, coconut, and pecans. Fold in the Cool Whip.
Transfer the mixture to the pie crust, and spread it out evenly. Refrigerate until fully chilled, 6 hours or overnight.
To serve, pipe 8 rosettes of Cool Whip around the exterior of the pie, and 1 rosette in the center. Top each rosette with a maraschino cherry. Sprinkle the 1/4 cup of chopped pecans on the top.
Notes
A store-bought 10-inch graham cracker crust is perfect for this recipe and makes it even quicker to assemble. If you prefer to make your own, you can follow the directions in our root beer float pie post.
Make sure to drain the pineapple really well so that the pie can properly set. Place the crushed pineapple in a fine mesh strainer, and use the back of a spoon to extract as much juice as possible.
The lemon juice helps thicken the filling and cuts the sweetness back. Either store-bought or fresh squeezed will work, you won't be able to tell the difference in this recipe.