Spray the inside of two silicone egg bite molds with non-stick spray.
Add cinnamon and nutmeg to the prepared cake mix. Stir to combine.
Spoon the cake batter into the egg bite molds until they are 3/4 full.
Tap the mold on the counter to settle batter and remove any bubbles. Cover with foil, sealing edges.
Insert trivet in the Instant Pot and add 1 cup water.
Carefully place the egg molds onto the trivet. Lock the lid in place and turn the knob to sealing.
Press the Manual or Pressure Cook button and set for 12 minutes.
When the time is up, let the pressure naturally release for 10 minutes, then quick-release the remaining pressure.
Carefully remove the molds from the pot. Place on a cooling rack and allow to set for 5 minutes before unmolding.
In a shallow bowl, mix together brown sugar and 1 Tbsp cinnamon. While still warm, roll each cake bite in sugar-cinnamon mix.