Prepare the cashew cream sauce and put it in the fridge one hour before you make the salad. It needs a little time for the sauce to thicken up. (If it's still thin after an hour, don't worry, it will thicken once you mix it into the potato salad and it chills in the fridge.)
Preheat the oven to 400 degrees.
Peel the sweet potatoes and cut them into 1-inch cubes. Lay them on a parchment lined tray and drizzle olive oil, garlic powder, salt, and pepper over the top. Toss to make sure the cubes are coated in the oil. Add a few sprigs of fresh thyme to the potatoes, bake for 20-25 minutes or until tender.
Let the potatoes cool, then add them to a large mixing bowl with the dried cranberries, pecans, green onions, and fresh sage.