1Mix molasses, shortening and brown sugar in a large bowl. Stir in flour, salt, baking soda, baking powder, and spices. Cover and refrigerate about 4 hours or until firm.
2Preheat oven to 375 degrees F (190 degrees C).
3Roll half of the dough at a time to 1/8 inch thickness or paper-thin on a floured cloth-covered surface. Cut into 3 inch rounds with floured cutter.
4Place about 1/2 inch apart on ungreased cookie sheet. Bake 1/8 inch thick cookies about 8 minutes; paper-thin cookies about 5 minutes or until light brown. Immediately remove from cookie sheet. Cool completely.
5To Make Frosting: Mix 1 cup confectioners' sugar, 1/2 teaspoon vanilla, and 1-2 tablespoons half-and-half until of spreading consistency. Spread frosting on cooled cookies.