Preheat the oven to 350 degrees F.
In a mixer, cream the butter until fluffy. Add the sugars, and cream together until light and fluffy. Add the egg and vanilla and mix well.
In a bowl, stir together the oats, flour, salt, and baking soda. Mixing, slowly add the oat mixture to the butter mixture and mix just until combined. Add raisins and mix just until combined.
Drop by tablespoonfuls onto the baking sheets, leaving at least 2-inches between cookies. Bake until browned and crispy around the edges, about 8 to 10 minutes. Let cool on wire racks and store in an airtight container.