Preheat oven to 350°. Line cookie sheet with parchment paper.
In a large bowl beat butter, brown sugar, granulated sugar, eggs and vanilla until light and fluffy. In a medium bowl whisk flour, baking soda, salt, cinnamon and nutmeg. Add dry ingredients to butter mixture, stirring until just combined.
Fold in rolled oats, raisins and walnuts (if desired). Drop dough balls about 2 inches apart onto a cookie sheet. (I use my medium sized cookie scoop.)
Bake for 10 minutes, rotate pan and bake an additional 2 minutes or until edges are lightly browned. Let cool completely on wire rack.
Notes
Nutrition information is an estimate only, based on 1 cookie serving with walnuts.