Alright so I've contemplated this idea in my head and I feel like the beer would be better for you but am open to the possibility this is partially bias because I like beer. This would be from the perspective of a college runner looking to maintain racing weight if that changes things at all.
Alcohol can block the absorption of certain vitamins...B vitamins I think...I'm not sure. Look it up.
What kind of beer? Big nutritional difference between 600kcals of a good Russian Imperial Stout and 600kcals of Miller.
Lets go with sierra nevada pale ale. Found a 12 pack for $12 so it's been my beer of choice lately.
A can of beer = 1 sandwich.
It depends on which of those 2 complements the rest of your diet. How many more calories do you need for the day? How many grams of protein have you had? No foods are inherently bad for you.
Daily or once a week? 600 calories of beer will cause you to gain less weight and once a week is frankly nothing for a college student. If you drank 600 calories per day that would be a bit too much alcohol. The cookies would have too much sugar though.
So once a week the beer is a clear winner. Daily neither makes much sense. Make that 12 pack last a week and you should be fine, provided you don't spiral into alcoholism and you have a good diet. Have a cookie after your workout if you want.