Preheat the oven to 450°. Pierce the sweet potatoes a few times and roast them in a large nonstick roasting pan for about 1 hour, or until soft and browned on the bottom. Let cool for 15 minutes. Remove the skin, leaving as much caramelized flesh as possible. Cut the potatoes into large chunks and transfer to a food processor. Add the lemon juice and zest, season with salt and pepper and process until smooth.
In a large nonreactive saucepan, combine the bourbon and brown sugar and bring just to a boil. Add the sweet potatoes and stir until blended.
The puree can be refrigerated for up to 1 day. Warm the sweet potato puree over low heat, then transfer to a large bowl and serve.
One Serving Calories 332 kcal, Cholesterol 0 mg, Total Fat .4 gm, Saturated Fat .1 gm.