Slow Cooker Brown Sugar Plum Butter

A wonderful way to use up a lot of plums! Using a slow cooker makes this pretty hands-off in comparison to jam, and there's less added sugar than jam too. This reduces down a lot; I made a half batch (1.6kg plums) and got 4 (!!) jars of butter. Really intensely plummy. Makes great foodie gifts. I added a wee bit of almond extract and that worked nicely! I feel this would turn into an amazing plum curd but haven't tried that... yet...