What are your favorite books based on folklore or fairytales?

My favorites are:

The Winternight Trilogy by Katherine Arden (Russian folklore)

Where The Dark Stands Still by A.B. Poranek (Russian folklore)

Spinning Silver by Naomi Novik (Russian fairytales)

I've also read and enjoyed:

Uprooted by Naomi Novik (Polish fairytales)

The Girl Who Fell Beneath The Sea by Axie Oh (Korean folklore)

The Folk of The Air series by Holly Black (Celtic folklore)

I'm excited to hear your recommendations!