Preheat oven to 350. Spread pistachios on a baking sheet and toast until just fragrant and starting to brown, around 6-8 minutes. This will depend a lot on your oven, so set a timer, keep a close eye on them, and stir after 4 or 5 minutes.

Pour hot pistachios in the bowl of a food processor and process until smooth and creamy, about 10 minutes. Add salt, honey, and cinnamon, and continue processing until smooth again, another 10 minutes. Taste and add more salt as necessary.

Store in an airtight container in the refrigerator.