Start by making the flax seed egg (see Notes). Add ½ of the chia seeds and 10 tbsp (½ cup) of water. Skip this step if you are using eggs.
Preheat oven to 350F/175C.
Line a 9x5 inch loaf pan with parchment paper and lightly grease with coconut oil (spray or use a brush)
Take ¼ of all nuts (so almonds and hazelnuts) and pulse in a food processor/ high speed blender until you have a coarse meal. This way the bread stays together better.
Mix all ingredients. Stir well until the batter is combined.
Press the batter into the lined loaf pan. Compact well.
Bake the bread for 45 minutes. Now remove the bread from the loaf pan (including the parchment paper) and transfer to a baking tray. Bake for another 15-20 minutes.
Let the bread cool completely before slicing. If not, the bread will likely crumble.