In which works is Poe's literary theory embodied?

In poetry. His aestheticism is embodied in his poetic creation theory, including Poetic Principles, Creative Philosophy, A Letter to Mr. B and so on.

In terms of novels. The debate about short stories mainly focuses on the comments on Hawthorne's Restated Stories and Creative Philosophy. First of all, he thinks that the length of the novel should be about half an hour to one or two hours, so that the author can concentrate on expressing his writing intention, thus controlling the readers' emotions and leaving an indelible impression on them.