Preheat oven to 350°; position oven rack in middle of oven; spray cookie sheets with nonstick cookie spray.
In a mixing bowl, add half the cake mix along with the nutmeg, oil, eggs, and rum extract; blend with an electric mixer on med-high for 1-2 minutes, until blended and smooth.
Stir in remaining cake mix and raisins with a wooden spoon until all dry ingredients are moistened.
Drop dough by teaspoonfuls, 2 inches apart, on cookie sheets.
Bake 9-12 minutes or until set at edges and just barely set at center when lightly touched.
Cool 1 minute on cookie sheet; transfer to wire rack to cool completely.
Icing: in a bowl, combine the powdered sugar, butter, and rum (add rum extract ½ teaspoon at a time and taste).
Add just enough milk to make icing of spreading consistency.
Drizzle icing over cooled cookies.