In a large skillet, heat oil over medium-high. Add turkey and salt; cook 4 to 5 minutes, until cooked through. Transfer turkey to a plate and increase heat to high. Add onion and garlic to skillet and cook 4 to 5 minutes, until translucent and tender. Return turkey to skillet and add marinara and pepper. Stir to combine and remove from heat.Advertisement
Line a 5-quart slow cooker with a plastic liner; coat liner with cooking spray. Layer a third of the meat sauce, 3 noodles and a third each of the zucchini, cheese and basil. Repeat layering twice, arranging top zucchini layer in a tiled or circular pattern and reserving the final third of the basil.
Cook on HIGH for 3 1/2 to 4 hours or LOW for 5 to 5 1/2 hours. Rest 15 to 30 minutes. Sprinkle with remaining basil, slice and serve.