Add all the juices, fruits, and spices to the inner pot of the instant pot. Stir in sweeteners and mix well.
Set the instant pot to pressure cook mode, and set the timer for 10-minutes.
After natural pressure release, open the lid. Use a ladle to smash the fruits, so they release juice. Strain and serve with fresh fruit slices and nuts.
For a spiked version, add strained plum cider and all the ingredients listed under the spiked version to the instant pot. Set the instant pot to “keep warm” and leave it for 30-minutes.
After 30-minutes, serve the spiked cider with fresh fruits and berries.