Made with simple ingredients and even better than your favorite bakery’s recipe, these oatmeal cookies are thick, chewy, and easy to bake for a delicious, crowd-pleasing treat!
Preheat oven to 350F with rack on lower middle position. Line baking sheets with parchment and set aside.
In a bowl, whisk flour, salt, baking powder, cinnamon, and nutmeg to fully incorporate.
In the bowl of a stand mixer fitted with paddle attachment set to medium speed, beat together the butter and both sugars until light and fluffy, a full 3 minutes. Add eggs one at a time and mix until combined. Reduce speed to low and add dry ingredients, beating just until combined; don't over-mix here. Gently mix in the oats and raisins, just until combined.
Roll dough into 2 TB sized balls and place 2 inches apart on lined baking sheets. Gently flatten each ball into a disk shape. Bake 13-15 minutes or just until edges are golden. Cookies will seem a bit under, but they will set upon cooling.
Optional Simple Icing: In a bowl, stir together powdered sugar and vanilla extract. Add water or milk until desired consistency is reached. Transfer into a piping bag or you can use a Ziploc bag and cut a small hole in the corner. Drizzle over cooled cookies. Icing should harden within 30 minutes.