First, start by preheating the oven to 35o degrees F, then line the baking sheet with a silicone mat or parchment paper then set aside.
In a medium bowl whisk the flour, baking soda, cinnamon, and salt until combined and set aside.
In the stand mixer bowl, cream the butter and both sugars together. Add in the egg and the vanilla and mix just until incorporated.
Add in the flour mixture and stir into the creamed butter, once that's incorporated add in the oats and cranberries and mix one last time.
Using a medium cookies scooper ( 1 1/2 tbsp ) scoop 20 equal balls and place them 2 inches apart on the prepared cookie sheet. Flatten each cookie using either your fingers of a fork to about 1/2 an inch thick.
Bake the cookies for 10-13 minutes, allowing them to sit and cool on the baking sheet for 5-10 minutes before transferring them to a wire rack.