Add the mango pieces, banana slices, apple, milk, sweetener, and ice cubes to your blender and blend until smooth. You can also use a high-speed blender like Vitamix Blender, which blends a super smooth and creamy milkshake in a few seconds.
If your milkshake is too thick, add some milk and blend again.
Serve immediately with some ice cubes if desired, and enjoy!