Rhubarb season is finally here! I don't know about you, but I can never get enough of its sweet-tart flavor and gorgeous rosy hue. This raspberry-rhubarb jam is incredibly easy to make thanks to a secret ingredient: a packet of raspberry Jell-O. Best of all, it's a freezer jam, which means you don't have to bother with sterilizing the jars or processing them in a hot water bath.