Cosslett, 53, helped to launch the innovative brand in 1982 - a time when owner Wall's was seen as the weaker sibling of the newly-merged Birds Eye Wall's business, and when ice-cream was being sold in supermarkets in four-litre tubs for 80p - at a loss.
'They gave me this thing that was being made by hand in the back of a factory and told me to do something with it,' says Cosslett, who had previously spent seven months driving around Liverpool in a Ford Fiesta, attempting to sell Wall's ice-cream to shops - and receiving answers he says were 'usually impolite'- as part of Unilever's graduate training programme.
'The launch was the first time anyone had added premium values to take-home ice-cream. The height of innovation before then was raspberry ripple flavour. It was also my first taste of marketing,' he says.
'It was an outlandish success and we were lucky we patented the concept early on.'
Cosslett, who studied economics and an MA in European Studies in his home city, at Manchester University, seems to put a lot of his career down to luck, including his appointment as chief executive of Inter-Continental Hotels Group (IHG), the world's biggest hotel operator by number of rooms, ahead of Wyndham Worldwide and Marriott International.
Unlike some of his industry counter-parts, he did not start off as bellboy or inherit the job through family ownership of the brand. In fact, rival operators saw his appointment in 2005 - following the ousting of predecessor Richard North - as something of an odd move.
It was Cosslett's high-profile marketing background, which encompassed a stint in Birds Eye's 'elite squad' during the heyday of frozen food in the mid-80s and 14 years at Cadbury Schweppes, that led to him being hand-picked for the job.
Since its de-merger from Six Continents, formerly Bass Breweries, in 2003, IHG had been busy transforming itself from a hotel owner into a hotel management and franchise company. The FMCG marketing expert was signed up for his skills in brand development and international operation, not to mention his expertise in innovation.
'Old-style hoteliers were still running the big operators, but the industry had begun to change,' says Cosslett, in an accent that retains the merest hint of his northern background. 'Bosses realised that they needed to sell the bricks and mortar to build brands, and they couldn't rely on internal promotions supplying the right people to lead this.'
He has stayed true to his Mancunian roots, despite three years of travelling as Unilever's marketing director for global agriculture - during which he discovered that 'fish markets at 4am are interesting places' - and a six-year spell at Cadbury Schweppes in Australia.
'I went to Ladybarn primary school
in Manchester, which was close to Noel and Liam Gallagher's house. It's such a great city,' says Cosslett, who plays the guitar in his spare time, if he is not playing golf or tennis. He also runs and swims.
Ladybarn must seem a far cry from his responsibilities today. IHG's fee-based model, in which it owns the brand rather than the hotels themselves, and owners pay into a central marketing fund, is the envy of many marketers. 'The advantage is that you can use other people's money to build the comp-any,' says Cosslett. This equips him with an annual marketing budget of $800m (£400m), a figure that can not be reduced in times of slow-down, because the funds have to be spent each year.
To date, his focus has been on the global expansion of the group's seven-strong brand portfolio, which includes InterContinental and Crowne Plaza, the mass-market Holiday Inn and Holiday Inn Express, extended stay chains Candlewood Suites and Staybridge Suites, and affordable boutique brand Hotel Indigo, which will make its UK debut in October.
Immediately after taking the helm of the company, which has its headquarters in Denham, Buckinghamshire, and leads the UK hotel market ahead of Premier Inn and Travelodge, Cosslett set an ambitious target to grow the business by 60,000 rooms in three years. He achieved this six months ahead of schedule.
He is now undertaking a major review of the company's brands. He relaunched upmarket chain InterContinental last year, making it more contemporary and targeting a slightly younger audience, and is currently overseeing a global brand makeover of Holiday Inn, which will be complete by 2011.
The $1bn (£500m) overhaul, covering more than 3000 properties worldwide, including the group's Holiday Inn Express sites, will be the first for the brand since its launch in 1952. It will be supported by an ad campaign, which breaks next year.
The work is being created by McCann Erickson, which was appointed to the budget chain's £10m EMEA advertising account in May.
A global relaunch of Crowne Plaza is next on Cosslett's to-do list as he aims to align all IHG's brands in Europe, the Middle East, Asia-Pacific and Africa with those in the US, the group's biggest market.
Asserting that 'the group needs to be centralised and all the brands need to be managed globally', Cosslett explains that he has a restructured the EMEA marketing department, creating vice-president roles for each region and marketing discipline, as well as creating a brand marketing department, ahead of the global brand review.
His international business prowess stems from his years in senior roles at Cadbury Schweppes, where, as managing director at Cadbury Schweppes Great Britain and Ireland, he led the integration of the Cadbury and Trebor Bassett confectionery businesses.
At InterContinental, the launch of Hotel Indigo, which Cosslett describes as an 'urban oasis' brand, is an indicator of where he plans to take the group. The hotel industry has traditionally segmented itself by price, but Cosslett is leading a shift toward segmentation by consumer preference.
'We are looking at launching other brands aimed at specific customer needs,' he says confidently. 'It's classic marketing.'
It is easy to see why Cosslett's reputation precedes him. He is a man with a clear vision and has wasted little time in putting this into action at InterContinental.
- 1979-1990 : Graduate trainee, Walls Ice Cream, rising to marketing director, Marine Harvest, Unilever
- 1990-2005: Marketing director, Schweppes GB, rising to president, EMEA, Cadbury Schweppes
- 2005-present: Chief executive, InterContinental Hotels Group
- Family: Married, two children
- Hobbies: Playing the guitar, tennis, golf
- Favourite brand: Guinness
- Holiday destination: Vietnam
- Sport to watch: Rugby
- Favourite car: Aston Martin
- Band in the charts: One Night Only