I wouldn't use granola for hamsters.You'd have to be extremely cautious with ingredients,including added sugars,which granola does tend to have.Absolutely no artificial ingredients(dyes etc),and you'd also want to be certain the preservative(if there is one)is specifically stated(E&C approved is not enough and is a loophole to allow cancer causing preservatives to be used).
Considering you're in the UK you'd be better off getting guaranteed safe straight grains and seeds and such from Rat Rations
They come in small quantities most of the time and you could try a variety of choices at once,depending on the food you use(Harry Hamster,perhaps?That is the best UK food for Syrians so definitely use it if you aren't already!).This gives far more flexibility than premade mixed granola options,and you can be certain nothing unsafe is used in them.
Quick cooking grains may be a poor choice by the way as they could potentially swell and cause blockages.