I love Bonne Maman strawberry jam and to hoard the jars it comes in, and this is my absolute favorite way to get at the last bits the sweet and sticky stuff that coats those glass walls. Just add a healthy shot of alcohol to the jar, close it, shake and strain, then use the jewel-toned booze in cocktails—or chill it and sip it on its own.
If you don’t drink alcohol, you can do what one very clever Twitter user did and rinse it with unsweetened black tea, or lemonade, or any other non-alcoholic beverage you think would benefit from a bit of fruity sweetness.