Combine all of the ingredients in a high-speed blender, and blend until a uniform slushie-like texture is achieved. Add more ice, if a thicker texture is desired, keeping in mind that additional ice will dilute the sweet vanilla flavor. (You can always add more maple syrup and vanilla, if you like.)
Pour into a large glass and enjoy immediately, with a spoon or a straw!
If you don't care for almond milk, you can substitute any other type of milk that you like. For a sugar-free version, you can also use liquid stevia, instead of the maple syrup, to taste.