For the starter, combine whole milk and lemon juice in a medium bowl and let thicken 10 minutes.

Add almond flour and granulated erythritol and stir to combine.

Transfer to a ziploc bag and remove as much air as possible. Then seal bag and allow to sit on counter for 3 days (see notes), massaging to mix ingredients 2 to 3 times a day.

On the 4th day, preheat oven to 325F and grease a 9 x 5 inch loaf pan very well.

Pour starter into a large bowl. Add one cup almond flour, 1/2 cup granulated erythritol, oil, eggs and vanilla extract and mix well. Set aside.

In a medium bowl, whisk together remaining 1 cup almond flour, remaining 1/2 cup granulated erythritol, vanilla pudding mix, whey protein powder, coconut flour, baking powder, baking soda, cinnamon and salt.

Add dry ingredients to starter mixture and stir until fully combined. Pour into prepared loaf pan.

For the topping, in a small bowl, whisk together granulated erythritol and cinnamon. Sprinkle over batter in pan.

Bake 50-60 minutes or until loaf is cooked through and a tester inserted in the center comes out clean. If you find that your loaf is browning too quickly, cover with foil for the last 15 to 20 minutes of baking.

*Please note that you are trying to sour the milk in this recipe. If you have concerns regarding the safety of doing so, simply add 2 more tbsp of lemon juice and continue directly to next step. It may not be as "authentic" but it should still taste great.