Preheat oven to 375 with two racks: one in the upper middle position and one in the lower middle. Prepare two bakinf sheets with parchment paper or generously spray with non-stick cooking spray.
Beat the butter, sugar, and eggs in a large mixing bowl with an electric mixer on medium speed for about 3-5 minutes, or until fluffy and slightly lightened in color.
Combine the dry ingredients (flour, baking soda, salt, cinnamon, ginger, nutmeg, and both types of oats) in a separate mixing bowl. Add them to the butter mixture 1/3 at a time, mixing on medium low until just combined. Scrape down the bowl and beat again for a few seconds. Add the raisins and stir by hand or with the mixer on its lowest speed.
Scoop cookie dough into one tablespoon-sized balls and place on the prepared baking sheets. They will spread during baking, so place them at least an inch and a half apart.
Bake for 12-14 minutes, until the edges are golden brown. For crispier cookies, bake a few more minutes. Remove cookies to a wire rack to cool. Store in an airtight container for up to five days.