Add butter, sugar, and Guinness to a large pot and bring to a boil. Keep on a rolling boil for 2 minutes.
Remove from heat and stir in remaining ingredients, once fully combined, plop large spoonfuls onto wax paper and let set for about an hour.
Notes
It's very important to have a rolling boil for 2 minutes, if you undercook then your cookies won't harden and if you overcook then your cookies will turn out dry and crumbly. Cookies will have a hard time setting if it's raining or humid.If mixture seems dry right off the bat, add a little more Guinness, if it seems soupy, add some more oats. This recipe should slightly spread, but not run, when plopped on the parchment paper.If you have a hard time getting cookies to set, place them in the fridge or freezer to help them along.Wrap individually if transporting to share so that cookies to not soften and stick to each other.