Place 1 cup of water in the Ninja Foodi or Instant Pot. Place the sweet potato on the rack or in the basket and pressure cook on high for 15 minutes* see post for details on size of sweet potatoes. When the time is up, do an immediate release.
While the sweet potato is pressure cooking, mix up the glaze by whisking together the balsamic vinegar, brown sugar, and dijon mustard in a small bowl.
Let the sweet potato cool until you can handle it comfortably. Dump the water from the inner pot.
Slice the ends off of the sweet potato and cut 4 equal sections that are about 1 ¼-1½" in size. Remove the sweet potato peel which should just fall off. You want the bacon to extend about ¼" above the sweet potato which creates a lip for the glaze to sit in.
Wrap each sweet potato wheel in the thick cut bacon and secure with a toothpick. Place a non-stick mat or a parchment round or even foil (poke some holes in it so the bacon grease drains some)in the basket or on the rack and set the sweet potato wheels on top.
Spoon the glaze on the top of each sweet potato. Don't worry if some drips off the sides, it will coat the bacon and candy the bacon as it cooks.
Close the crisping lid and select air crisp on 330°F/165°C or the closest temperature to that on your appliance. Air Crisp/Air Fry for 20-25 minutes.
Add about a Tablespoon of marshmallows on top of each sweet potato wheel. Broil for about 5 minutes. Remove and allow to cool slightly. Remove the tooth picks before serving.
Serve & Enjoy!