2Combine oats, flour, baking soda, and salt in a medium bowl. Mix well.
3In a large bowl, combine brown sugar, butter or margarine, buttermilk, and vanilla. Beat with electric mixer on low speed for 1-2 minutes, until well blended. Add oat mixture to sugar mixture. Stir until dry ingredients are moistened. Stir in raisins.
4Shape dough into 16 balls (1-1/2" diameter). Place on a large cookie sheet 2" apart. Flatten cookies to 1/4" thickness using the back of a spoon. Dip the spoon in water to prevent it from sticking to cookies. Bake for 13-14 minutes, until tops of cookies are dry to touch and bottoms are golden brown. Do not overbake! Remove from tray immediately and let cool.