Important: if you are making homemade cream of coconut, you must make it first and allow time for it to cool before starting the recipe. See notes.
In a blender, add 1 cup cream of coconut, 3/4 cup pineapple juice, 2 tablespoons lime juice, 1 teaspoon rum extract, 1 teaspoon molasses (optional), and 10 ounces frozen chopped pineapple, about 3 cups.
Blend until completely smooth, about 1 minute.
Transfer the mixture to a container with a lid. Freeze the mixture for 45 minutes to 1 hour, until it is partially frozen.
Return the mixture to the blender and blend again for just a few seconds, until it is smooth and creamy.
Serve immediately. Garnish with maraschino cherries, parasol picks (the official name for the cute umbrellas), straws, and a wedge of pineapple.