This oat bar is a great way to get fresh fruit into snacks, although the results weren't entirely satisfactory. I followed this recipe, adding orange zest to the oat mixture and leaving out the ginger in the fruit. I also added 30g chopped toasted hazelnuts to the portion of oat mixture set aside for the topping, and didn't add any icing. I cut the 8x8" bake into 8 portions - 16 small squares wasn't a realistic size for our appetites!
Although the bars were delicious, with the consistency of a chewy flapjack, the excess juice from the fruit made the bottom layer very sticky and slightly too soggy. The flavour from the orange zest came through well, and really complemented the rhubarb. The hazelnuts also added a welcome crunch to the topping, which helped overcome the general sogginess of the bars.
While looking for a recipe, I also saw some which cook the rhubarb to a purée and thicken the juices, before using it between the oaty layers, and I think this might be an improvement to what is basically a really good idea.