Soak raisins in hot water for 30 minutes, then drain.
Meanwhile, in a small bowl, sifft together flour, cinnamon, baking soda, and salt
Using an electric mixer fitted with paddle attachment, cream together butter and sugars on medium speed until light and fluffy, scraping down frequently. Take care not to overbeat
Add flour mixture to creamed butter and sugar and mix on low speed until combined. Mix in oats, followed by drained raisins, egg and vanilla
Use a 1/4 cup measure to scoop dough onto a parchment-paper lied baking sheet. Flatten each blob with base of measuring cup. Cover baking sheet with plastic wrap and refrigerate 4 days (optional)
To bake cookies: Preheat oven to 350°F. Bake until cookies are golden-brown on the outside but still soft in the middle, about 17 minutes. Remove from oven and let rest on baking sheet a few minutes, then transfer to a rack to cool.