Preheat oven to 450 degrees F. Place the sweet potato pieces on a sheet pan and drizzle with 1 Tbsp olive oil, 1 tsp kosher salt, and pepper and toss well. Arrange pieces in one layer and roast for 25 to 30 minutes, turning once. In a large skillet, toast steel cut oats over medium heat for 5 minutes until fragrant and nutty, stirring constantly. Boil water in a small saucepan. Transfer toasted oats to a large bowl and pour over boiling water and 1/4 tsp salt. Cover and let stand for 20 minutes or until oats have absorbed all the water. Fluff with a fork (note that oats are purposely undercooked to retain texture and bite).* To prepare the dressing, whisk together olive oil, vinegar, shallot, lemon zest, and salt & pepper. In a large bowl, combine the cooled oats, sweet potatoes, spinach, avocado and cranberries. Add dressing and toss well to combine. Serve cold or at room temperature.