• Take out your stand mixer with the paddle attachment. (If you don't have a stand mixer, you can use a hand mixer. But make sure you cream the butter and sugar until light and fluffy)
• Position the oven rack in the center of the oven and preheat the oven to 350 F. The oven will preheat while you prepare the cookie dough.
• Line a baking sheet with parchment paper or grease a baking sheet.

Make the dough

• Start by adding the room temperature butter, white sugar, and brown sugar to the stand mixer. Cream until light and fluffy.
• Add the egg, sourdough discard, vanilla extract, and molasses to the bowl. Beat until just combined and smooth.
• In a medium sized bowl, combine the flour, baking soda, cinnamon, salt, and rolled oats. (Add chocolate chips or raisins if using)
• Add the dry ingredients to the wet ingredients and mix until just combined.
• (You can chill the dough for a few hours in the fridge or bake right away.)

Scoop the cookie dough

• Using a cookie scoop, drop the dough on a baking sheet with at least 2 inches in between each cookie. I prefer to make smaller cookies, around 2 tablespoons per cookie.

Time to bake

• Bake the cookies in the middle rack for 10-12 minutes at 350 F. The cookies should have a light golden brown color and will look a bit wet in the middle. This is ok. They will continue to bake for a few minutes after leaving the oven. It is better to underbake slightly than to overbake the cookies. Let the cookies rest for 10 minutes on the baking sheet and then transfer to a cooling rack.