Heat oven to 375°F. Soak toothpicks in cold water at least 10 minutes. Line bottom of a 15 x 10-inch cookie sheet with foil. Place brown sugar in a shallow bowl.
Stack bacon; cut crosswise into 3 equal pieces. Wrap each piece bacon around a Li'l Smokie, roll in brown sugar. Use a soaked toothpick to skewer all the way through the center and out the opposite side. Place half of the prepared smokies on cookie sheet.
Bake 10 minutes; turn over and continue baking 5 minutes or until bacon is golden brown. Repeat baking with remaining half. Let cool before serving. Serve warm or at room temperature on a lettuce-lined platter. Have mustard in a small bowl for dipping if desired.