Soak your raisins in warm water for 10 minutes,, then dry them well by blotting them with a paper towel.
Meanwhile, cream the butter, cinnamon, nutmeg, dark brown sugar, and white sugar together using a hand mixer or a stand mixer fitted with paddle attachment. Cream until smooth.
Once smooth, add eggs, one at a time, and mix on high until combined, about 1 minute.
Add vanilla, molasses, and mix together. Set aside.
In a separate bowl, combine flour. Baking soda, and salt, whisking them together.
Slowly add the wet ingredients to the flour mixture, until combined.
Mix in the oats and raisins, on low speed. The dough should be pretty thick and sticky.
Cover dough and refrigerate for 30-60 minutes to prevent spreading.
When ready to bake, Preheat oven to 350°F
Line two baking sheets with parchment or a silicone mat, and roll the dough into balls of about 2 Tablespoons of dough.
Place them on the prepared sheet 2 inches apart.
Bake for 12-14 minutes until lightly browned on the sides, but soft and doughy looking in the center.
Remove from oven and cool on the baking sheet for 5 minutes. Then transfer to a cooling rack.