DOUGH:

3 tbsp. unsalted butter, softened
2 tbsp. sugar
1/4 tsp. salt
1/2 of a whole egg, vigorously beaten until frothy (reserve the other half for
the sweet-potato filling)
2 tbsp. cold milk
1 c. all-purpose flour

SWEET - POTATO FILLING:

2 to 3 sweet potatoes (or enough to yield 1 c. cooked pulp), baked
1/4 c. packed light brown sugar
2 tbsp. sugar
1/2 egg, vigorously beaten until frothy (reserved above)
1 tbsp. heavy cream
1 tbsp. unsalted butter, softened
1 tbsp. vanilla extract
1/4 tsp. salt
1/4 tsp. ground cinnamon
1/8 tsp. ground allspice
1/8 tsp. ground nutmeg

PECAN PIE SYRUP:

3/4 c. sugar
3/4 c. dark corn syrup
2 sm. eggs
1 1/2 tbsp. unsalted butter, melted
2 tsp. vanilla extract
Pinch of salt
Pinch of ground cinnamon
3/4 c. pecan pieces or halves

For the dough: Place the softened butter, sugar, and salt in the bowl of an electric mixer; beat on high speed until the mixture is creamy. Add the 1/2 egg and beat 30 seconds. Add the milk and beat on high speed 2 minutes. Add the flour and beat on medium speed 5 seconds, then on high speed just until blended, about 5 seconds more (overmixing will produce a tough dough). Remove the dough from the bowl and shape into a 5 inch patty about 1/2 inch thick. Lightly dust the patty with flour and wrap in plastic wrap; refrigerate at least 1 hour, preferably overnight. (The dough will last up to one week refrigerated.)

On a lightly floured surface, roll out dough to a thickness of 1/8 to 1/4 inch. Very lightly flour the top of the dough and fold it into quarters. Carefully place dough in a greased and floured 8 inch round cake pan (1 1/2 inches deep) so that the corner of the folded dough is centered in the pan. Unfold the dough and arrange it to fit the sides and bottom of pan; press firmly in place. Trim edges. Refrigerate 15 minutes.

For the sweet-potato filling: Combine all the ingredients in a mixing bowl. Beat on medium speed of electric mixer until the batter is smooth, about 2 to 3 minutes. Do not overbeat. Set aside.

For the pecan pie syrup: Combine all the ingredients, except the pecans, in a mixing bowl. Mix thoroughly on slow speed of electric mixer until the syrup is opaque, about 1 minute; stir in pecans and set aside.

To assemble: Spoon the sweet-potato filling evenly into the dough-lined cake pan. Pour the pecan syrup on top. Bake in a 325 degree oven until a knife inserted in the center comes out clean, about 1 3/4 hours (Note: The pecans will rise to the top of the pie during baking.)

Cool and serve with Chantilly Cream. Store pie at room temperature for the first 24 hours, then (in the unlikely event there is any left) refrigerate.