If you prefer a sweeter version, you may or agave nectar.
Peel a guanabána and remove the seeds from the flesh. Put in a blender with about 3 cups of water and blend. Add another 2 cups of water. You may strain through a sieve for smoother consistency. Add sweetened condensed milk with lime juice, ground nutmeg vanilla extract. Blend ingredients again. Serve with or without ice.