In a large bowl, cream butter and sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in molasses and sour cream. Combine the flour, ginger, baking soda, allspice, cinnamon and nutmeg; gradually add to the creamed mixture and mix well. Stir in raisins and walnuts.
Drop by tablespoonfuls 1 in. apart onto greased baking sheets. Bake at 375° for 10-12 minutes or until the edges begin to brown. Remove to wire racks to cool. Yield: 8 dozen.