First, preheat the oven to 180 C / 350 F and line a loaf pan with parchment paper.
Using an electric mixer or a food processor, blend the eggs until fluffy, light in colour and double the size - about 2 minutes.
Add the sweetener, peanut butter and almond milk and continue blending until a smooth batter.
In a separate bowl, stir together the remaining dry ingredients - almond flour, coconut flour, salt and baking powder. Then, add them to the wet ingredients and mix until well-combined.
Wait 3 minutes to let the coconut flour absorb the moisture. Now, check the consistency of your batter. It should be soft. If your peanut butter was very runny, you may need to add an additional tablespoon coconut flour. If it was firmer, you may need to add a splash of almond milk.
Fill the batter into the prepared bread pan and bake for about 60 minutes. Check the bread after 45-50 minutes. If it is golden brown, loosely cover the top with aluminium foil to prevent burning.
Let cool completely before slicing.