First make the cinnamon swirl filling. Whisk together the brown sweetener and cinnamon until well combined. Set aside.

Grease a 7" springform pan well. Place the trivet on the bottom of your Instant Pot and add 1 cup of water.

In a large bowl, whisk together the almond flour, sweetener, protein powder, baking powder, and salt.

Add the eggs, melted butter, vanilla extract, and water and stir until well combined.

Spread half of the batter in the prepared pan, and sprinkle with half of the cinnamon filling mixture. Swirl with a knife or spoon.

Add the remaining batter cinnamon mixture, then swirl and spread the batter evenly in the pan.

Cover the top and the bottom of the pan with foil. Place the pan on the trivet in the Instant Pot. Close and lock the lid. Set the valve to sealing. Set on the "cake" setting for 60 minutes. (Or manual HIGH if you don't have a cake setting).

When cooking is complete, let the pressure reduce naturally for 15 minutes, then open the vent to allow any additional steam to release. Remove the pan carefully and remove the foil.