Combine oatmeal and milk in a large bowl.
Cover and let sit in refrigerator for 1 hour.
Preheat oven to 400° F.
Lightly spray a muffin tin with vegetable oil.
Remove oatmeal mixture from refrigerator and add margarine, egg, brown sugar and raisins.
In another bowl, mix dry ingredients together.
Add to oatmeal mixture.
Stir only enough to moisten the flour.
Batter should be lumpy.
Fill muffin tins two-thirds full with batter.
Bake 15 to 20 minutes.