Preheat your oven to 300°F (150°C) and prepare a 4x4 inch baking pan by lining it with parchment paper or greasing it.

In a bowl, whisk together eggs and avocado oil until frothy (2-3 minutes). Optionally add erythritol for sweetness.

Add Greek yogurt to the egg and oil mixture and stir gently until smooth.

In another bowl, combine almond flour, protein powder, baking powder, xanthan gum, and salt. Whisk until evenly distributed.

Gradually pour the dry ingredients into the wet mixture, stirring with a spatula until just combined.

Pour the batter into the prepared baking pan and smooth the top. Bake for 50-55 minutes until golden brown and a toothpick comes out clean.

Cool the bread in the pan for about 15 minutes, then transfer to a wire rack to cool completely before slicing.