Cigar City Brewing Co.’s Maduro Brown Ale clone

(5 gallons/19 L, all-grain)
OG = 1.059  FG = 1.017
IBU = 25  SRM =  32  ABV = 5.5%

This is far darker than the BJCP guidelines for an English brown and pushes past the upper limit in terms of ABV, but it shows you cannot contain American brewing culture behind the bars of strict BJCP styles, that irresistible urge to push a beer bigger and bolder will not be stopped.

Ingredients
8.25 lbs. (3.7 kg) Simpsons Extra Pale Ale Malt
1.4 lbs. (0.64 kg) Simpsons Crystal T50^TM malt
1 lb. (0.45 kg) flaked oats
15 oz. (425 g) Briess Victory® Malt
11 oz. (312 g) Simpsons Brown Malt*
5.5 oz. (156 g) chocolate malt
5.1 AAU Northern Brewer hops (60 min.) (0.6 oz./17 g at 8.5% alpha acids)
3.9 AAU Willamette hops (15 min.) (0.7 oz./20 g at 5.5% alpha acids)
Wyeast 1335 (British Ale II), SafAle S-04, or LalBrew Nottingham yeast
¾ cup corn sugar (if priming)

*Be careful if substituting, at 170 SRM Simpsons Brown Malt is a lot darker than other brown malts. Coffee malt is an appropriate substitute.

Step by Step
Cigar City Brewmaster Wayne Wambles suggested to mash a little higher than normal, so I’d mash in at 154 °F (68 °C); this will give you a higher final gravity and thicker mouthfeel. Mash the pale malt and oats for 40 minutes then stir in the crystal, Victory®, brown, and chocolate malts. Begin recirculation and slowly raise to mash out temperature of 168 °F (76 °C), hold for 5 minutes before beginning sparging.

Collect 6.5 gallons (24.6 L) wort in the kettle and bring to a boil. Boil for 60 minutes adding the hops according to the ingredients list. After the boil, give a long stir to create a whirlpool then let the break material settle. Chill down to yeast-pitch temperature, about 66 °F (19 °C). Aerate if using a liquid yeast strain and then pitch the yeast.  

Ferment at 68 °F (20 °C) until terminal gravity reached, about one week. Condition for an additional week then transfer to a keg and force carbonate or bottle and prime to 2.4 v/v. 

Partial mash option: Replace 6 lbs. (2.7 kg) of the extra pale malt with 3.5 lbs. (1.6 kg) of extra light dried malt extract. Place the extra pale malt, flaked oats, and Victory® malt in a large muslin bag then submerge in 2 gallons (7.6 L) hot water to stabilize at 154 °F (68 °C) and hold for 40 minutes. Add in the chocolate, brown, and crystal malts in a separate muslin bag and hold for 15 minutes. Remove both grain bags and place in a colander over the kettle. Slowly rinse the grains with 2 gallons (7.6 L) of hot water, then top off kettle to 6.5 gallons (24.6 L). With the heat turned off, stir in the malt extract. Bring the wort up to a boil and then follow the remainder of the all-grain recipe instruction