Make the Brine: Add water, apple cider vinegar, salt, sugar, cinnamon sticks, and pickling spice mix to a pot. Bring to a boil, then reduce the heat to low and simmer for 2 minutes. Remove from the heat and allow to cool.
Make the Pickles: Remove the rind and core from a fresh pineapple before slicing into long spears. Turn a large jar onto its side, and line it with the pineapple so they’re well-packed in. Dice the jalapeño and add the pieces to the jar along with a couple more cinnamon sticks. Pour the cooled brine into the jar, making sure everything is fully submerged. Seal with a tight lid, flip upside down, and let pickle at room temperature for at least 4 hours.
