Suggested Reading for Protestant Mysticism and Contemplative Spirituality

The Website of Unknowing has a short list they describe as "several books to read with an eye to how Christians from the Anglican and Reformed traditions have explored the call to go deeper into the Christian spiritual life.":

The Voyage of the Dawn Treader by C. S. Lewis
Practical Mysticism by Evelyn Underhill
Mystical Hope by Cynthia Bourgeault
Gift From the Sea by Anne Morrow Lindbergh
Hind’s Feet on High Places by Hannah Hurnard

Ones I've read are in bold print. The one I haven't read is the only one with an author still living.