Drain the soaked walnuts and place them in an upright blender. Add the filtered water to the blender. Blend the mixture on high for about 2 minutes, or until you have a fluid, creamy "milk." Strain the milk with a fine mesh strainer over a large bowl or pitcher. Push the walnut pulp in the strainer with the back of a spoon to get all of the milk out. Pour the strained milk into a sealable container and refrigerate until ready to use.
The milk will separate, so just shake it every time you use it. Milk keeps in the fridge for about a week.
Banana Bread Shakes
In an upright blender, combine the walnut milk, sliced bananas, cinnamon, nutmeg, vanilla powder and maple syrup (and ice, if using). Blend on high until you have a creamy and smooth mixture. Add the cacao nibs and blend for 10 seconds more--just so that you have little cacao "chips" throughout the drink.
Pour the banana bread shakes into glasses and garnish with toppings if you like. Serve cold.