A gentle reminder that the OP was specifically asking about the Sam Smiths beer, whose ingredients are listed as :
water, malted barley, yeast, cane sugar, hops,CO2
All the flavour comes from those ingredients, no pecans required. British recipes tend to be simple. And never underestimate what the yeast brings to the party.
Cane sugar probably means invert #3, although it could be one of the other sugar derivatives like refiner's syrup.
Typical homebrew recipes I've seen are along the lines of 78% English pale, 10% amber, 10% crystal, 1.5% chocolate to OG: 1.048 which obviously misses out any sugar.