Preheat your oven to 350°F / 175°C.
Grease and line a standard loaf tin (approx. 8x4 inch) with parchment paper.
In a large bowl or a food processor, combine the dry : almond flour, coconut flour, flaxseed meal, salt, and baking soda.
Whisk or pulse until well combined and free of lumps.
Add the wet to the dry mixture: eggs, melted coconut oil, sweetener, and apple cider vinegar.
Mix until the batter is smooth and thoroughly combined, but be careful not to overmix.
Pour the batter into your prepared loaf tin and smooth the top with a spatula.
Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean and the top is golden brown.
Let the bread cool in the tin for at least 20 minutes before transferring it to a wire rack to cool completely. This step is crucial for the bread to set properly.
Let the bread cool completely before slicing. Gluten-free breads are fragile when warm and slicing too early will cause them to crumble.