Malton-based Yorkshire Baker has had to go into 24-hour production to keep up with demand for the steak pie from M&S customers.
The artisan supplier's £6 'The Best' range pie flew off the shelves - with 20,000 selling out in just two days. It has become the chain's fastest-selling product EVER, with sales 40 per cent higher than predicted.
These are the nine best bakeries in YorkshireYorkshire Baker's founder, farmer's daughter and butcher Gill Ridgard, moved to Malton in 2007 and set up the company, specialising in gourmet pastry products such as handmade sausage rolls, which are sold in delis and farm shops across North Yorkshire. Since entering into partnership with Cranswick PLC in 2012, she now employs several bakers.
Marks and Spencer are attributing the pie's success to a huge social media campaign which has seen a promotional video made by Leeds-based creative content studio Powerhouse shared 400,000 times on Facebook.
The short film shows each stage of the pie being made.