Preheat your oven to 350°F (175°C) and line a loaf pan with parchment paper or grease it generously.

In a large mixing bowl, whisk together the six eggs, Greek yogurt, and melted butter (or coconut oil) until smooth and creamy.

Add the baking powder, salt, xanthan gum (or psyllium husk), and almond flour (if using) to the wet mixture, then stir until well-combined and slightly thickened.

Pour the batter into the prepared loaf pan, using a spatula to smooth the top.

Bake for 35 to 45 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean.

Let the bread cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely before slicing.