1. Preheat oven to 425°. Pierce potatoes several times with a fork. Arrange in a single layer in a jelly-roll pan, and bake 25 to 35 minutes or until just tender. Transfer to a wire rack; cool completely (about 30 minutes).
2. Meanwhile, bring orange juice and next 5 ingredients to a simmer in a small saucepan over medium-low heat. Simmer, stirring often, 5 minutes or until thickened. Remove from heat.
3. Peel sweet potatoes, and cut crosswise into 1 1/2-inch pieces, discarding ends.
4. Melt 1 Tbsp. butter in a 10-inch cast-iron skillet; cook over medium heat 1 minute or until butter begins to brown. Carefully add sweet potatoes, cut sides down, and cook 5 minutes. (Do not stir; move the skillet across the cooking eye to promote even browning.)
5. Pour orange juice mixture over potatoes, and cook 10 minutes or until glaze is slightly thickened. Transfer potatoes, seared sides up, to a serving platter; pour glaze over potatoes, and sprinkle with salt.
To make ahead, prepare as directed through Step 2. Place potatoes in a zip-top plastic freezer bag and glaze in an airtight container; refrigerate up to 3 days. Reheat glaze in a saucepan over medium heat 10 minutes. Proceed as directed in Steps 3 through 5.