In a medium bowl whisk the egg, salt, heavy cream until foamy.
Add the melted butter, coconut flour or almond flour, baking powder, parmesan cheese and stir well.
Transfer the batter to a greased mug. Tap the mug on the counter for a few time to remove the air bubbles. Microwave for 90 seconds or until the top is firm.
For the oven version: Preheat the oven to 350F. Bake the 90 second bread into an oven-safe container for 10 to 15 minutes.
