Fill a large pot with water and a 1 teaspoon kosher salt and wheatberries. Bring to a boil, cover and reduce heat to a low simmer for 1 hour, until wheatberries are tender enough to chew. Drain and set aside.
Meanwhile, preheat oven to 400*.
Toss cubed squash with 3 tablespoons olive oil, 2 teaspoons brown sugar, 1/2 teaspoon cinnamon and 1/2 teaspoon salt.
Line a pan with foil and fill with squash. Cover with more foil and bake for 20 minutes.
Remove squash, uncover and add 2 cups cranberries. Bake for another 15 minutes, until squash is fork-tender and berries have softened.
Prepare dressing by combining all ingredients in a jar and shaking well.
Coat wheatberries with dressing. Toss to combine.
Add squash and cranberries, pom arils, and arugula and toss everything well.
Serve slightly warm, room temp or chilled.