I found this recipe on JaP; it had been pinched from the above site but the pinch was faulty so I went ahead and did a manual copy. The pic I used is from that site; I have credited the photographer in pic description.
Heat oven to 350°. Place potatoes on a foil-lined baking sheet; bake until tender, about 1½ hours. Peel and transfer to a food processor along with brown sugar, bourbon, butter, 1 tsp. salt, cinnamon, ginger, allspice, nutmeg, pepper, eggs, and pineapple; puree. Transfer to a 9" x 13" baking dish; bake until heated through, about 25 minutes.
While casserole bakes, bring sugar, and ¼ cup water to a boil in a 1-qt. saucepan over high heat; attach a candy thermometer to the side of the pan, and cook, without stirring, until syrup reaches 250°. Meanwhile, place remaining salt, vanilla, and egg whites in a large bowl; beat on medium-high speed of a hand mixer until soft peaks form. While beating, slowly drizzle in hot syrup, and beat until meringue is thickened and cooled.
Heat broiler to high. Spread meringue over casserole; broil until lightly browned, about 2 minutes.
Personal NOTE: You can probably use canned chunk sweet potatoes to decrease prep time. Just add the ounces on each can until you get 5 1/2 lbs (88 ounces) or thereabouts (cans may weigh less or more than 16 ounces--it's okay to have slightly less or slightly more than the given amount). Since I am unsure if the can's measurement includes the liquid, you might want to get one extra can, just in case; so when you taste it before baking, if it seems like it needs more sweet potato flavor you can add some.
Also, the instructions do not indicate whether the pineapple should be drained, so I would drain it first and reserve the liquid, then if the pineapple-sweet potato mixture seems like it's too dry you can add in the pineapple water.