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, 4 tablespoons of the butter, vanilla extract, and ¼ cup water and stir until well combined. Add more water to achieve a thick but spreadable consistency.

Spread a little more than 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 over top and another 1 ½ tablespoons of the cinnamon mixture (Reserve about 2 teaspoons for after baking). Swirl a little and then spread out the batter evenly in the pan.

Tightly cover the top and the bottom of the pan with foil to reduce excess moisture seeping in during cooking. Place the pan in the Instant Pot. Close the lid and seal the vent. Set on the 'cake' setting for 60 minutes.

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.

Preheat your broiler to high and set an oven rack in the middle position. Brush the top of the bread with the remaining ½ tablespoon of butter and sprinkle with the remaining cinnamon mixture. Place on the center rack so that it’s not too close to the heat.

Broil until the top is golden, 3 to 5 minutes. Remove and let cool at least 15 minutes, then run a sharp knife around the inside of the pan and release the sides.

In a small bowl, whisk together the sweetener, cream, and vanilla until smooth. Add water ½ teaspoon at a time until it thins out to a drizzling consistency. Drizzle over the cooled bread.