Roast walnuts at 225 degrees on a baking sheet for 30-40 minutes, until very aromatic. If using a dark, non-stick sheet, watch carefully and flip a few times (they will burn faster). Let cool for 15 minutes.
Add walnuts and almonds to a blender and blend on high until smooth and oily. Add sugar, cinnamon, and salt, and blend for another 10 seconds. Store in a jar or airtight container in the fridge.
Recipe by Veggie Ninjas at https://www.veggieninjas.com/cinnamon-roll-walnut-butter/