In a small microwave-safe bowl, add the raisins along with ¼ cup of water. Cover with plastic wrap and microwave for 30 seconds, then allow to sit covered until needed.
In the bowl of a stand mixer, beat together butter, sugars, and vanilla extract for 2-3 minutes. Add the egg, then mix until combined.
In a medium-sized mixing bowl, combine flour, oats, baking soda, cinnamon, nutmeg, and salt. Whisk to combine. With the mixing speed on low, gradually add dry ingredients, mixing until no flour pockets remain. Remove the bowl from the stand and fold in raisins (drain any excess moisture from the bowl before adding them). Cover the bowl and place the dough in the refrigerator to chill for 1 hour before baking.
Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius). Line baking sheets with parchment paper or baking mats, and set aside.
Using a standard-sized cookie scoop, place chilled cookie dough balls onto the prepared cookie sheets. Place in the oven and bake for 10-12 minutes, or until the edges of the cookies begin to turn golden brown in color. The centers should look slightly underbaked; they will firm up once cooled. Remove from oven and allow cookies to cool on sheets for 3-4 minutes before transferring to a wire rack to cool completely.
Notes
-You could easily swap out the raisins for chocolate chips (just increase the vanilla extract by ½ tsp. and omit the cinnamon and nutmeg). Sometimes I'll add toffee chunks too!STORE Soft Chewy Oatmeal Raisin Cookies in an airtight container at room temperature for up to one week. To FREEZE, just place them in a freezer bag. They can also be frozen for up to three monthsTo REHEAT, microwave a cookie for 10-15 seconds or warm it in a preheated oven at 300 degrees Fahrenheit (150 degrees Celsius) for 5-10 minutes.