Preheat oven to 350~. Combine flour, spices, & baking soda. With an electric mixer at medium-low, beat butter & sugar until fluffy. Add egg, vanilla, & lemon zest, & beat until combined. Beat in half the flour mixture. Add 1/4 milk, then beat in remaining flour mixture until well blended. Stir in dates, raisins, & walnuts. Drop by rounded teaspoonfuls onto an ungreased baking sheet. Bake until browned, about 10 min. Stir about 4-6 tbsps of milk into icing sugar to make a thin glaze. Spread the glaze on the cooled cookies.