I would recommend Javascript The Weird Parts. Good pacing and clear exploration of the languages ‘quirks’ and a general tour of vanilla js. Then you can dive into how your own framework can be created, also interesting for obvious reasons.
This course really pushed my js knowledge forward!
Definitely a great course, started learning JS using that one.
After watching that I would recommend https://github.com/getify/You-Dont-Know-JS and that should give one a solid base.