1. Preheat oven to 400 degrees F. and grease a muffin pan.
2. In a large bowl, stir together the oats, flour, baking powder, brown sugar and salt.
3. In a second bowl, stir together the vanilla, egg, butter and milk until they are well blended.
4. Make a well in the center of the dry ingredients and add the liquid ingredients until they're combined. Stir in the raisins.
5. Spoon the batter into the muffin pan and bake for 15 to 18 minutes or until a toothpick comes out clean. Remove the muffin pan and cool muffins in the pan on a wire rack for four minutes. Remove the muffins from the pan and continue cooling them on the rack.