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

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

Make filling: Combine all ingredients in a mixing bowl. Beat on medium speed of an electric mixer until smooth, 2 to 3 minutes. Do not over beat.

Make syrup: Combine all ingredients except pecans in a mixing bowl. On slow speed of an electric mixer, mix thoroughly until syrup is opaque, about 1 minute. Stir in pecans.

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

Cool and serve with whipped cream.