For years, travelers returned from Linz, Austria, singing the praises of linzertorte, a dessert made with a buttery-nut crust and filled with raspberry jam. This recipe is a bar-cookie adaptation of the popular torte.
Beat butter in a medium mixing bowl with an electric mixer on medium to high speed for 30 seconds. Add granulated sugar, lemon peel, cinnamon, and cloves; beat until combined. Beat in egg and liqueur, brandy, or water until combined. Stir in the 1 1/2 cups flour and hazelnuts or almonds with a wooden spoon. Form dough into a ball. Wrap in plastic wrap and chill for 1 hour.
Line a 13x9x2-inch baking pan with foil, extending foil 1 inch beyond ends of pan. Grease foil. Pat half of the dough into the bottom of the greased foil-lined pan. Stir the 2 tablespoons flour into remaining dough and refrigerate. Spread jam evenly over dough on pan.
Roll refrigerated dough between two pieces of waxed paper into a 15x10-inch rectangle. Cut rectangle into 1/2-inch-wide strips about 15 inches long. Chill dough strips on the waxed paper or place strips on paper in freezer about 20 minutes or until very firm and easy to handle. Peel strips from waxed paper. Carefully place half of the strips diagonally across jam about 1/2 inch apart. Piece strips of dough together as necessary. Place remaining strips at right angels to first strips.
Bake in a 350 degree F oven about 30 minutes or until crust is golden. Cool in pan on a wire rack. Cut into squares. Lift out bars on foil. Carefully remove foil. Just before serving, sift powdered sugar over squares, if desired. Makes 32 cookies.