"This initiative…is at the forefront of the digital revolution whilst offering our consumers a different way of sending confectionery gifts," the company said in a statement.
The new application is one step up from virtual gifts.
Since Facebook launched its developer platform to allow third-party applications to sit on the social networking site last year, thousands of 'widgets' have been created which allow users to give virtual flowers and other make-believe gifts to their friends.
However, the idea behind the new application, entitled 'Celebration', is that Facebook users can now buy real chocolate treats for friends.
Consumers wishing to participate in the scheme choose the chocolate gift, and pay for it using PayPal, an e-commerce business that allows for safe credit card-buying via the internet.
A Facebook message is then sent to the recipient who has to provide a mobile number in exchange for a voucher code.
This code can then be exchanged for the chocolate bar in one of 12,500 participating PayPoint stores across the UK, the company claims.
Marc Lewis, founder and chairman of The Light Agency, which helped develop the technology, claimed that the Celebrate application allows consumers to buy gifts for friends at the touch of a few buttons.
"And with more than 50 per cent of Facebook users returning to the site each day, it gives us and Mars an unprecedented reach and opportunity to build a business highly relevant to people's lives," he said.
Mars said it was too early at this point, however, to predict the level of sales the platform will generate.