Preheat the oven to 350°F and line a loaf pan with baking paper.
In a mixing bowl, whisk together the almond flour, coconut flour, Erythritol, salt and baking powder.
In another bowl, whisk together the eggs, butter, Greek yogurt, milk, and vanilla extract.
Fold the dry ingredients into the wet ingredients until a smooth batter forms.
Add the shredded zucchini and stir gently.
Pour the batter into the prepared loaf pan and bake for 40-45 minutes, or until a skewer inserted at the center of the loaf comes out clean.
Allow it to cool in the pan completely, before removing and slicing. Serve at room temperature or store covered in an airtight container for up to a week.