Check out the thread @
https://www.homebrewtalk.com/forum/threads/surly-darkness-recipe.273322/
Notably post #7. Would seem that Anderson7000 also stumbled upon this thread based on the %s they reported? Anyway it turns out fantastic, though Darkness does change slightly from year to year...
Made this in January according to skibb's layout. Compared last night to the barrel aged 2017 darkness...other than missing the oak/whiskey notes this is a dead ringer for the retail version. Thanks for the recipe.