With all those beautiful plums coming in, this easy overnight crockpot plum butter is a great way to prolong the summery goodness well into the fall! Stock up on plums and make several batches of this plum butter because it's so good that you're going to be craving it all year! Simply add the plum butter to sterilized jam jars and seal. This plum butter also makes for a great foodie gift to give your friends!