Heat oven to 425ºF. Arrange sweet potatoes in greased 8x8x2-inch baking pan.
Combine 2 tablespoons butter and 1/4 cup brown sugar in small saucepan; bring to a boil. Drizzle over sweet potatoes. Bake at 425ºF for 15 minutes on rack in center of oven.
Meanwhile, melt remaining 1 tablespoon butter. Stir in remaining 1/4 cup brown sugar, bacon and pecans.
Remove sweet potatoes from oven. Set oven to broil leaving rack in center of oven.
Sprinkle bacon mixture over top of sweet potatoes. Broil on center rack for 2 to 3 minutes until sugar is bubbly and pecans start to brown.