The UK retailing giant claims to be the first to commercially sell the sweet sandwich which could lead to further collaboration between confectioners and bakers in the snacking industry.
According to market research group TNS, the UK sandwich market was valued at £2.8bn (€4.1bn) in September this year. However it is a sector which has seen minimal innovation and is typically dominated by retailers at the luxury end of the market such as chain store Pret à Manger.
Now Tesco are hoping the unusual variety will catch the eye of consumers and open up the possibility of rejuvenating the image of store-bought pre-packed sandwiches.
Tesco sandwich buyer James Cornish said: "One of the world's most popular home made sandwiches is peanut butter and jam yet no one has ever marketed that - now [the inventor] may have opened the door for a whole new different kind of sarnie in a market possibly worth tens of millions of pounds."
Sales are far from assured for the chocolate and banana creation however given the recent backlash against obesity and, in particular, efforts from Government watchdogs and consumer groups to halt unhealthy eating habits among children.
The banana and chocolate filling was originally the brainchild of a youngster representing children's charity Whizz-kidz which Tesco has been supporting as part of its 'charity of the year' scheme.
Other children from Whizz-kidz have been asked to design the outer packaging for the new product.
The sandwich went on sale at 700 UK Tesco stores at the start of this week priced £1.30 (€1.92) - of which 50p is donated to the children's charity.