Scrub the delicata squash clean, pat dry, and dice into ½-inch rounds (length-wise).
Scoop out the seeds and remove the stringy parts, using a grapefruit spoon.
In a large mixing bowl, toss the squash with salt, pepper, cinnamon, and olive oi. Coat well.
Line a large baking sheet with parchment. Spread the squash out in a single layer over the sheet. Bake in a middle rack about 20 minutes on the first side and flip the rinds to bake 8-10 minutes additional.
In the meantime, prepare the sauce in one bowl. Cover and set aside in the fridge. In a mixing bowl, Toss the arugula with salt pepper to taste and drizzle with oil and lemon juice.
To serve, spread the arugula over a large serving platter. Place the roasted delicata squash all over. Sprinkle with cranberries and raisins, if using. Drizzle with a touch of sauce over the squash or serve it on the side to pass around the table. Serve warm or at room temperature.
You can also use toasted and chopped walnuts, almonds, or pistachios if you prefer not to use cranberries/raisins.