Soak the almonds at least overnight, up to 24 hours, in 2 cups of the water. Drain, then place in a blender with 1 1/2 cups of water. Add vanilla, and dates, maple syrup, or cinnamon, if using. Blend on high for 3 minutes, scraping down the sides of the blender as needed. If you like a thinner consistency, add up to 2 more cups of the water and blend for 1-2 more minutes. Allow to rest for 1 hour in the blender. Taste, and add more maple syrup, another date, or one more sprinkle of cinnamon if needed. Blend well, at least another minute.