Baked Sweet Potatoes with Amaretto

5 pounds sweet potatoes, scrubbed (see note)
3/4 cup butter (1 1/2 sticks), divided
1/2 cup packed dark brown sugar
1/4 cup orange marmalade
1/2 teaspoon salt
6 tablespoons amaretto liqueur, divided
24 almond macaroons or 20 gingersnap cookies

Butter a shallow 3-quart baking dish; set aside. Position oven rack in center. Preheat oven to 450 degrees F.

Lightly oil potatoes and place on oven rack. Bake until soft, about 40 minutes for 8-ounce potatoes to 60 minutes for very large potatoes. Cool potatoes, then peel and mash well with 1/2 cup butter, sugar, marmalade and salt. Stir in 4 tablespoons liqueur.

Spread mixture evenly in prepared dish. Preheat oven to 350 degrees F.

Using a food processor fitted with steel blade, chop cookies coarsely. Add remaining 1/4 cup butter and remaining 2 tablespoons liqueur; pulse to make a coarse crumb mixture. Sprinkle crumb topping over potatoes. Bake assembled casserole until steaming hot, about 35 to 40 minutes. Makes 12 servings.

NOTE: Canned sweet potatoes can be substituted for fresh.