Preheat oven to 350 degrees Fahrenheit. Line baking sheet with parchment paper and set aside. Place raisins in a bowl or cup and cover with water.
½ cup raisins
Using stand mixer with paddle attachment fitted or hand mixer, beat the butter, brown sugar, and granulated sugar on medium-high speed until they form a smooth brown paste (about four minutes).
6 tablespoons butter, ¾ cup brown sugar, 1 tablespoon granulated sugar
Add in the egg and vanilla and continue to mix for about three minutes or until the mixture is creamy and thick.
1 egg, 2 teaspoons vanilla paste
Meanwhile, whisk together flour, cinnamon, baking soda, nutmeg, cardamom, salt, and white pepper in mixing bowl. Drain water from the raisins.
¾ cup flour, 1 teaspoon cinnamon, ½ teaspoon baking soda, ½ teaspoon nutmeg, ¼ teaspoon cardamom, ¼ teaspoon fine sea salt, ⅛ teaspoon white pepper
Add flour mixture to butter mixture and beat on medium until it starts to come together then add in oats, drained raisins, and walnuts and continue mixing until uniform. Use silicone spatula or kitchen spoon to stir a few times by hand.
1 ½ cup rolled oats, ⅓ cup walnut pieces
Use cookie scoop to scoop dough onto prepared baking sheet, leaving at least two inches of space between each ball of dough so that they don't stick together as they spread.
Transfer pan to middle or upper rack of oven and bake for 12-14 minutes or until edges are golden brown and set. Middles of cookies will still be gooey when they come out of the oven but they'll set as the cookies cool. Cool for at least 15 minutes before serving.