Step 1

Preheat oven to 400°F. Lightly butter a 2-quart baking dish. Roast potatoes on a rimmed baking sheet until a knife easily inserts into centers, 1 hour. Cool enough to handle, then remove and discard skins. Coarsely chop potatoes. Reduce oven temperature to 375°F.

Step 2

Mash together potatoes, bourbon, 2 tablespoons butter, and 1 tablespoon sugar in a bowl. Season with salt. Transfer to prepared baking dish. Combine pecans, cinnamon, remaining 4 tablespoons butter, and 3 tablespoons sugar in a second bowl. Sprinkle over potatoes.

Step 3

Bake until bubbly and warmed through, 30 to 35 minutes.