Prepare the Tart Crust. Cool completely on a wire rack.

Spread the pecan halves in a single layer in a shallow baking pan. Bake in a 350 degree F oven, stirring occasionally, for 8 to 10 minutes or until lightly toasted. Remove from oven.

Meanwhile, in a large saucepan, heat and stir 1-1/4 cups of the Butterscotch Sauce over low heat until warm. Remove from heat. Stir hot nuts, chocolate, and butterscotch-flavored pieces, stirring until the pieces are melted. Pour filling into prebaked tart shell. Bake in a 350 degree F oven for 14 to 15 minutes or until edges are bubbly.

Cool on wire rack. Serve with whipped cream and chocolate curls, if you like. Makes 10 servings.

In a medium bowl, mix 1-1/2 cups all-purpose flour, 2 tablespoons sugar, 1/2 teaspoon baking powder, and 1/8 teaspoon salt. Using a pastry blender, cut 1/4 cup cold unsalted butter into flour mixture until pieces are pea-size. In a small bowl, mix 1 lightly beaten egg and 1 tablespoon ice water. Gradually stir egg mixture into flour mixture. Using fingers, knead dough until a ball forms, adding up to another 1 tablespoon ice water, a little at a time, if needed. Don't overmix; dough should feel slightly sticky. Use hands to flatten and shape into a 6-inch round disc. Wrap in plastic wrap and chill in refrigerator for 45 to 60 minutes or till firm.On a floured surface, roll dough into an 11-inch circle. Transfer to a greased 9-inch fluted tart pan with a removable bottom. Press into fluted sides of tart pan; trim edges. Don't prick unbaked tart shell. Chill for 30 to 60 minutes. Line tart shell with a double thickness of foil. Bake in a 400 degree oven for 10 minutes. Remove foil. Bake 5 to 6 minutes more or till light brown. Cool on a wire rack. Makes one 9-inch tart crust.

In a heavy medium saucepan, melt 1/2 cup unsalted butter over low heat, stirring often. Increase heat to medium. Stir in 2/3 cup granulated sugar, 2/3 cup packed brown sugar, 3/4 cup light-colored corn syrup, 2 tablespoons water, and 3/4 teaspoon salt. Bring to boiling; stir constantly. Reduce heat; simmer, uncovered, for 5 minutes, stirring often (you'll see big, slow bubbles as it boils). Remove from heat. Carefully whisk in 3/4 cup whipping cream and 2 teaspoons vanilla (the sauce may sputter). Use 1-1/4 cups of the sauce for the pie. Allow remaining sauce to cool. Cover; refrigerate remaining sauce. If you like, reheat over low heat and stir before serving over ice cream. Makes 3 cups sauce.