When ready  to bake, preheat oven to 350 degrees. Adjust oven racks to lower and middle.

In your mixer bowl, add butter and using a whisk attachment, cream until light and fluffy, stopping to scrape down as needed. Add the sugars and continue to cream, scraping as necessary, until fully incorporated. Add the eggs, one at a time, beating well between each addition and scraping as necessary.

Switch to paddle attachment.

In a separate bowl, combine the flour, salt, baking powder & nutmeg and whisk together. Add to the butter mixture at low-speed and beat until just combined. Add the oats, slowly mixing and scraping until fully incorporated. Stir in the raisins and/or optional ingredients by hand.

Divide dough (a 1/3 cup scoop works well for this) into 20 or so large balls, about 2″ in diameter. Line your cookie sheets with parchment or a silicone baking mat. If desired, refrigerate for one hour and up to several days, well covered.

Place cookies, about six on a sheet (do not press down on them) and bake from 18 to 25 minutes, turning and rotating sheet pans about halfway through. Cookies are done when they’re browned around the edges, are slightly golden and look just a little under done in the center.

Pull the cookies off the cookie sheet, parchment and all and let set up for about 10 minutes before moving them to a cooking rack to cool completely.

Notes:

• Dough may be frozen and baked from the frozen state. Increase time by a minute or two.
• Keep the baked cookies in a cool dry place for up to 10 days.