Preheat the oven to 325°Lightly grease an 8x4-inch loaf pan.

In a large bowl, beat together cream cheese and salt using a hand whisk.

Add melted butter, avocado oil, heavy whipping cream, and eggs. Beat until thoroughly combined.

Add the baking soda, cream of tartar, xanthan gum, and whey protein isolate. Mix until batter is smooth, and there are no visible lumps.

Pour the batter in a loaf pan, and bake for 50 minutes or until an inserted toothpick comes out clean.

Place on a cooling rack for 10 to 15 minutes. Slice and serve.