Unite said that 80% of workers voted in favour of the deal, which over two years, inclusive of bonuses, is worth up to 17.5%.
It covers more than 1,000 workers at four sites at Bournville, Birmingham, Chirk, Wales and Marlebrook in Hereford.
The union also said it had delivered a separate 25% boost in holiday pay.
Cadbury owner Mondelēz said it was pleased to have reached the agreement that recognised staff but also allowed the company to remain competitive.
'Set the standard'
Unite national officer for food and drink, Joe Clarke, said: “Unite negotiated this deal over three months with Cadbury and it sets the standard for the rest of the food manufacturing sector, which is performing very strongly.
“Unite will be negotiating with other food manufacturing companies in the coming months and we will be bargaining for our members in those workplaces to also receive rises that take into consideration the rising cost of living and high profits of their employers.”
A Mondelēz International spokesperson: “We are pleased to have reached a two-year agreement with Unite for our UK chocolate manufacturing colleagues.
"This agreement represents an improved overall package including not only base pay but other elements which enable us to both recognise our colleagues’ important contributions but also remain competitive in our manufacturing operations.”
The news comes as the confectionary manufacturer has managed to trade mark its iconic ‘Cadbury Purple’
The High Court found in favour of Cadbury UK Limited. It partially overturned the decision of the UK Intellectual Property Office (UKIPO) Hearing Officer allowing the registration of Cadbury’s colour per se purple trade mark – a trade mark for a specific colour (defined by Pantone 2685C) without contours and with no description defining its use.