- Preheat oven to 350°F.
- In a bowl, stir together the ground beef, breadcrumbs, allspice, nutmeg, pepper, cayenne, and 1 tsp of salt.
- Press mixture into the bottom and sides of a 9-inch pie plate up to the rim; refrigerate for about 15 minutes.
- Meanwhile, in another large bowl mash together the sweet potatoes and remaining ingredients and the remaining 1/2 tsp salt with a potato masher until mixture is smooth.
- Spoon the sweet potato mixture into the uncooked meat shell.
- Bake in a 350 degree oven for about 50 minutes or until knife inserted in center comes out clean.