The Leinster centre, who likes to sail in his free time, was at the helm of everything Ireland 'A' did - and they did plenty in taking the silver trophy in emphatic fashion at Dick's Sporting Goods Park.
McFadden followed up his two tries in the previous game against Georgia with three conversions and a penalty to add to tries from Devin Toner, Isaac Boss, Sean Cronin, Felix Jones, Johne Murphy and John Muldoon.
Jonathan Sexton, another member of Leinster's Heineken Cup-winning squad, wielded plenty of influence in open play and kicked 10 points.
Speaking afterwards, McFadden said: "We're delighted to have beatean England in this last match. We thought it would be a bit closer but we gelled a lot better than them and put in a very good performance.
"There's loads of talent in the team so let's hope there's a lot more to come from this group of players.
"It's been great to have Declan Kidney and the senior coaches here looking after us and it has certainly given us extra motivation to succeed in this tournament.'
While McFadden's overall contribution across the tournament earned him his 'Minute Man' trophy, flying full-back Felix Jones was receiving the man-of-the-match champagne for his try-scoring contribution.
"The forwards have been quality all tournament and it's testament to the likes of Neil Best who have been on the road with the senior team as well for the last five weeks and yet just got on with it today."
The Saxons' grip on the cup after two years was less than secure as Ireland 'A' led 20-12 at half-time before the floodgate opened after the break, with their only consolation coming in tries from Ben Woods and Tom Varndell to add to Stephen Myler's four penalties.
England Saxons captain Phil Dowson said: "Ï'm shellshocked. We took a pasting and there are no excuses. It wasn't a pretty sight at all.
"We just didn't look after our ball whereas, in contrast, Ireland 'A' did. We didn't work hard enough at the breakdown and we have learned some harsh lessons today.
"We have to go away and look at the videos but we just were not good enough today."