Place the sweet potatoes in a large bowl, then drizzle with 1 1/2 teaspoons olive oil and sprinkle with brown sugar, salt, and pepper. Toss until evenly coated. Arrange in a single layer on the prepared baking sheet, and bake for 20-25 minutes, until the sweet potatoes are fork tender, turning them once half-way through so that they cook evenly.
Place rack in the upper third of your oven and preheat oven to 425 degrees F. Line a large baking skeet with parchment paper or a silicone mat. Set aside.