Bring all ingredients to room temperature.
Line two baking sheets  with parchment paper or Silpat and set aside.
Soak raisins in hot water for 10 minutes, then drain. (optional)
Beat together butter, brown and white sugar in a bowl for 2 minutes.
Add vanilla and egg and beat to combine.
In a bowl sift together flour, cinnamon, salt and baking soda.
Add dry ingredients to the butter and beat to combine. Stir in the oats, then raisins.
Chill the batter for 15-30 minutes.
Preheat oven to 350 F (175 C).
Using a 2 tablespoon cookie scoop, scoop out dough and roll into balls.
Place on the baking sheet and bake for 11-12 minutes, until the edges are golden.
Let the cookies cool down for 5 minutes on the baking sheet, then transfer to a cooling rack.
Store in an air-tight container at room temperature for 5 days.