Sift flour, baking soda, salt, and cocoa together; set aside.
Cream butter with extract; add sugar gradually, beating until fluffy. Add the egg and beat well.
Alternately add dry ingredients with water, mixing until blended after each addition. Add rolled oats gradually, stirring well.
Drop by teaspoonfuls 2-inches apart onto ungreased cookie sheets. About 15 doz. cookies.
Bake at 350°F about 12 minutes.
NOTE: If desired, after addition of rolled oats, mix in any one of the following: 1 cup chopped dark seedless raisins, 6 ounces semisweet chocolate pieces, 1 cup drained, chopped maraschino cherries, or 1/2 cup chopped candied cherries and 1/2 cup chopped candied pineapple.