In a mixing bowl, cream shortening and sugar. Add egg; mix well. Beat in molasses. Combine dry ingredients; add to creamed mixture and mix well. Drop by rounded teaspoonfuls onto greased baking sheets. Bake at 350 for 8-10 minutes. Remove to wire racks; cool. For frosting, cream the sugar, butter and lemon peel in a mixing bowl. Gradually add lemon juice, beating until frosting reaches desired spreading consistency. Frost cookies