6 tablespoons unsalted butter

3 pounds sweet potatoes, peeled and cut into 1 1/2-inch pieces

3/4 cup packed dark brown sugar

1/4 cup fresh apple cider

3 tablespoons bourbon

Kosher salt

Preheat the oven to 400°.

Grease a 9-by-13-inch glass or ceramic baking dish with 1 tablespoon of the butter.

In a large saucepan of salted boiling water, blanch the sweet potatoes until barely tender, 8 to 10 minutes. Drain well.

Spread them in the prepared baking dish in an even layer.

In a small saucepan, melt the remaining 5 tablespoons of butter with the brown sugar. Whisk in the cider and bourbon, season with salt and bring to a boil.

Cook over moderately high heat, stirring, until the sugar dissolves, 1 to 2 minutes.

Pour the mixture over the sweet potatoes and gently stir to coat.

Bake the sweet potatoes until tender and the sauce is syrupy, 35 to 40 minutes.