Cream together butter and sugar until light and fluffy. Add molasses and eggs and beat well. Sift together flour, salt, soda, baking powder and spices; stir in raisins and nuts.
Add flour mixture to molasses mixture, blend well.
Spread evenly in a greased 12x8-inch baking pan. Bake in a preheated 350 degree oven for 30 minutes. Frost with confectioners' sugar icing while warm. Cool and cut into squares.
Tip: I mix a little milk with about a cup of confectioners' sugar to the consistancy I want.