First, prepare your springform pan by greasing and flouring it. Place a 2-foot piece of tin foil and a paper towel underneath. This will help stop excessive condensation from getting into the cake.
Chop the apples into bite-sized pieces and add the cinnamon and 1 Tbs sugar. Mix well to combine and set aside.
Add all of the remaining dry ingredients together, stirring to mix well. Mix the wet ingredients together in a small bowl or large measuring cup. Add them to the dry ingredient mixture and stir well to combine.
Add the cinnamon apple mixture to the cake batter and mix gently. You don’t want to overmix, so just stir it enough to distribute the apples throughout.
Transfer the cake batter into the springform pan and smooth the top with a spatula.
Add 1 cup of water to your Instant Pot. This is necessary so that the Instant Pot can build up steam pressure. Add the trivet. Place the wrapped springform pan on top of the trivet (so that it’s not touching the water) and secure the lid.
Cook on manual for 1 hour. When the timer is done, let your Instant Pot Natural Release (NR) before releasing the lid.