Spray the inside of the cake pan with nonstick cooking spray.
In a large bowl, combine the cake mix, 1 cup water, vegetable oil, and eggs. Prepare according to the package.
Add the grated carrots and stir to evenly distribute.
Pour into the prepared cake pan until almost ¾ full. Do not overfill the pan, if there is extra keep for another use.
Add 1 cup of water in the Instant Pot and place trivet.
Wrap the cake in aluminum foil and place on the trivet.
Close the lid and set the valve to the SEALING position. Pressure cook on HIGH pressure for 35 minutes.
Meanwhile, in a medium bowl, combine cream cheese frosting and powdered sugar. Stir until smooth and well-blended. Set aside.
When the cooking time is done, do a QUICK RELEASE, and carefully open the lid.
Remove the cake from the Instant Pot and unwrap the foil. Allow the cake to cool for 25-35 minutes and release from the springform pan.
When the cake has fully cooled, spread the cream cheese frosting over the top and sides of the cake evenly.
Sprinkle the chopped pecans across the cream cheese layer. Slice into serving portions.