Peel and chop the zapotes (mamey). Combine with the remaining ingredients (sugar, vanilla, milk, and ice) and blend in a heavy-duty blender until it is creamy and smooth.
Serve immediately.
Notes
Nutritional information is estimated because zapote is not in the food database used to calculate nutrition info.
Lactose-free, vegan milkshakes
Use almond milk (or your preferred substitute). I hear from our readers (I haven't tried it) that coconut milk is great for this purpose.