My current method of learning new languages/frameworks is to read the theory (documentation/book) and write questions as I read. Then, I would try to apply the concept (exercise/project). The next day, I would start by reading the questions I wrote. If I know the answer, I just quickly answer it in my head and move on to the next question. If I don't know the answer, I would look it up. Also do add some sort of tally mark next to questions you have successfully answered so that you don't have to keep reading them each day as your list of questions grows (though it might be worth answering a few times to commit it to long term memory).

I think this incorporates spaced repetition and active recall well enough while not being entirely theoretical.