Place the raw almonds and salt (1/2 tablespoon per cup of almonds) in a glass or ceramic mixing bowl and pour in the filtered water. Swirl the mixture around a few times to help the salt dissolve.
Cover with a kitchen towel or paper towel and place in a cool, dry area on your counter. Soak for 12 hours.
Drain and rinse your almonds. After soaking, the water may have a brown or chalky appearance- this is normal and comes from the tannins in the almond skins, and the salt. Discard the water and thoroughly rinse the almonds with fresh, cold water.
If using a dehydrator, spread the almonds out on the trays in a single layer, making sure not to crowd them. Set the dehydrator temperature to 130 °F for 12 hours, or until crispy.
If you're using an oven to dehydrate the nuts, spread them out in a single layer on a rimmed baking sheet lined with parchment paper. Place in an oven set to the lowest temperature setting (use the "warm" setting if necessary). To prevent the almonds from getting too hot, leave the oven door cracked slightly. Dehydrating in the oven will take less time, because the temperature is usually higher.
Check on the almonds periodically during the dehydration process. You'll know the almonds are done dehydrating when they have a "crispy" bite and are no longer soggy in the center. If your almonds are rubbery, they're not done dehydrating. Your dehydration temperature may be too low, or the nuts may be overcrowded on the trays. Keep dehydrating them until they have that "crispy" bite!
Now it's time to roast the almonds. Preheat your oven to 350 °F. Put the almonds on a rimmed baking sheet lined with parchment paper and toast for 10 minutes. Stir the almonds halfway through.
Let the almonds cool down before putting them in your food processor. I recommend waiting until they're room temperature, but you can also blend them when they're still slightly warm.
Blend the almonds until they are thick and creamy. This will take some time- 10-15 minutes or more. Scrape down the sides every couple minutes and keep going! Add the coconut or avocado oil 1-2 tablespoons at a time, as needed, to help the nuts process smoothly.
When your almonds have processed down to a thick, creamy paste, add salt, cinnamon and vanilla powder (if using) to taste. Blend the mixture once more to evenly season.
Let the almond butter cool down to room temperature. Store it in an airtight glass jar in the fridge for up to two weeks. If you notice any signs of spoilage, dispose of immediately.