In a mixing bowl, combine the oats and cashew milk. There should be just enough milk to fully submerge all of the oats -- add an extra splash if necessary. Cover the bowl and refrigerate for at least 4 hours, or up to overnight.

Preheat the oven to 300ºF and grease a sheet pan with a dab of coconut oil. Spread out the walnuts in a baking dish in a single layer.

Stir the sugar, melted coconut oil, vanilla, salt, and cinnamon in with the soaked oats, then spread them out on the sheet pan in an even layer.

Bake the walnuts for 15 minutes, until they're aromatic and toasted.

Bake the granola for 1 hour and 15 minutes, stirring it every 25 minutes so that it browns evenly. You'll need to scrape the oats off of the pan -- a wooden spatula is a great tool for this job.

When the granola is done, it will be a deep, golden brown. Remove the sheet pan from the oven and let the granola cool to room temperature.

Chop the walnuts, then combine them with the cooled granola. Store the granola in an airtight container for up to two weeks.