Beat butter and shortening until light; gradually add sugar, and beat until mixture is fluffy. Beat in eggs and vanilla, blending thoroughly. Sift together flour and salt; add to creamed mixture. Stir in caraway seeds. Roll dough thin, not more than 1/8", and cut in 2" diamonds with sharp knife or cookie cutter. Place 1/2" apart on lightly greased baking sheet. Bake in 325 oven 10 to 12 minutes. Remove from baking sheets and cool on racks. Spread cookies with White Mountain Frosting; sprinkle with pink sugar. WHITE MOUNTAIN FROSTING: Combine 1 cup sugar, 1/8 teaspoon cream of tartar and 1/4 cup water in small saucepan. Place over heat and stir until sugar dissolves. Continue cooking to soft ball stage (236) on candy thermomter. Meanwhile, add 1/2 teaspoon salt to 1 egg white; beat until stiff. Pour hot syrup in a fine stream into egg white, beating constantly until frosting is of spreading consistency. SOURCE: Farm Journal's Great Home Cooking In America (pg. 104-105) ----