Preheat oven to 400-degrees F and spray two large baking sheets with nonstick cooking spray. Thinly slice* sweet potatoes and lay out pieces in a single layer on the sheets. Using a silicone brush, coat each slice of sweet potato with olive oil (you'll use about 1 tablespoon). Season with salt and pepper and bake for 10-12 minutes per side or until golden (keep an eye on them to prevent burning). Remove from oven and set aside to cool.
To prepare the tapenade, place olives, scallions, sundried tomatoes and remaining oil in a food processor fitted with a steel blade. Season with 1/4 teaspoon salt and 1/4 teaspoon black pepper and pulse until well combined, but still slightly chunky. Top each piece of sweet potato with tapenade and serve.
Use a hand-held mandoline to make easy, even slices.