Prepare pastry. Use your hands to slightly flatten pastry dough on a lightly floured surface. Roll dough from center to edge into a 13-inch circle. Wrap pastry around rolling pin. Unroll into an ungreased 11-inch tart pan with a removable bottom. Ease pastry into tart pan, being careful not to stretch pastry. Press pastry into the fluted side of tart pan. Trim edge. Place a double thickness of foil over pastry in the bottom of tart pan. Bake in a 450 degree F oven for 5 minutes; remove foil. Bake 5 minutes more; set aside.
Beat cream cheese, 1 egg, granulated sugar, and 1/4 teaspoon vanilla in a small mixing bowl with an electric mixer on medium speed until combined. Cover and chill in refrigerator for 30 minutes. Spread in pastry-lined tart pan.
For filling, beat the 2 eggs slightly in a large mixing bowl with a rotary beater or a fork. Stir in the corn syrup. Add the brown sugar, butter, orange peel, and 1/2 teaspoon vanilla, stirring until sugar is dissolved. Stir in nuts and apricots.
Place pastry-and-cream-cheese-lined tart pan on a baking sheet on the oven rack. Carefully pour filling into pan. Bake in a 350 degree F oven about 40 minutes or until a knife inserted near the center comes out clean. Cool for 1 to 2 hours on a wire rack. Refrigerate within 2 hours; cover for longer storage. Garnish with whipped cream and pistachio nuts, if desired. Cut into wedges to serve. Makes 12 servings.
Orange Tart Pastry
Stir together flour and sugar in a medium mixing bowl. Using a pastry blender, cut in butter until the pieces are pea-size. Stir together egg yolks, water, and orange peel in a small mixing bowl. Gradually stir egg yolk mixture into dry mixture. Using your fingers, gently knead dough just until a ball forms. If necessary, cover with plastic wrap and chill in refrigerator for 30 to 60 minutes or until dough is easy to handle.