Pumpkin Ice Cream Pie

1-9 or 10 inch graham cracker crust
1 cup mashed, cooked or canned pumpkin
1/2 cup brown sugar
1/2 teaspoon salt
1 tablespoon pumpkin pie spice
1 quart vanilla ice cream, softened
1 cup whipping cream, whipped, or non-dairy whipped topping

Put graham cracker crust in freezer to chill. Blend together pumpkin, sugar, salt, and pumpkin pie spice. Fold in softened ice cream. Fill crust and place in freezer to refreeze. Make a border around edge with whipped cream. Garnish with pecan halves if desired.