Preheat oven to 425 degrees F. Line a baking sheet with parchment paper.
While the oven is preheating, prepare the squash by slicing it in half and scooping out the seeds in both halves. Then, slice into rings. Combine the olive oil, cinnamon, and sea salt. In a large bowl, coat the squash with the olive oil mixture and toss until coated. Place squash pieces on the lined baking sheet.
In a small food processor (or using a knife), coarsely chop the pistachios. Sprinkle the chopped pistachios on each delicata squash ring, coating the entire surface. Bake for 20-25 minutes or until squash are tender. Enjoy!
You can save the delicata squash seeds for roasting! Rinse and dry the seeds, and add a touch of olive oil and sea salt before roasting for 20 minutes at 400 degrees F.