Cream butter; gradually add 1/2 cup sugar, beating until light and fluffy. Add next 6 ingredients, beating until smooth.
Add flour, 1/2 cup at a time, beating well after each addition (dough will be stiff ) . Press dough into 6- x 1 1/2-inch rectangles. Carefully transfer to un-greased cookie sheets. Bake at 300° for 15 to 20 minutes. Remove to wire racks, and sprinkle with powdered sugar.