Begin by preheating your oven to 400 degrees F.
Then, line two baking sheets with foil and spray with a non-stick cooking spray. Set aside.
Wash your delicata squash and then cut in in half. Use a spoon or melon baller to scoop out the seeds. Then, slice each half into 1/2-inch-thick rings. Discard the end pieces.
Next, you'll need three dishes. In the first dish, place the flour. In the second dish, whisk together the mayonnaise, buttermilk and dijon mustard. And in the third dish, whisk together the bread crumbs, parmesan cheese, parsley, salt, and pepper.
Begin by dipping a delicata squash ring into the flour. Shake off any excess flour. Then dip the ring into the mayonnaise mixture, again allow any excess to drip off. Finally, coat the ring with the bread crumb mixture and place it on a prepared baking sheet. Repeat this process with the remaining rings.
Bake the rings for about 15 minutes or until the bottoms begin to brown. Remove the rings from the oven and turn each one over. Place them back in the oven and bake for 10-15 more minutes or until the rings are nicely browned and tender.
Meanwhile, prepare the creamy herb dip by whisking together mayonnaise, sour cream, buttermilk, herbs, garlic, salt, and pepper.
Serve the baked delicata rings warm with the creamy herb dip.