Wash and pit the cherries (if you have a cherry pitter, like
this one from OXO, it’ll go much more quickly). Chop about half of the cherries and then transfer all of them to a large non-reactive stock pot. Add the lemon juice, vanilla bean scrapings, and vanilla bean, then heat over medium heat, uncovered, stirring occasionally with a silicone spatula. Once the mixture starts bubbling, set your timer and cook for another 20-25 minutes, crushing the cherries several times with a potato masher. Be especially vigilant stirring near the end so as not to burn the cherries and juice.