Preheat your oven at 160 celsius degrees with the fan mode or 180 celsius degrees if you use a conventional oven. I prefer using the fan mode for better heat distribution.
Start by expanding the chia seeds with 75 ml of water – allow to rest for 10 minutes and mix from time to time to make sure all the seeds are in contact with water. In a bowl mix all the ingredients but remember to keep half the walnuts for later. Add the expanded chia and mix well with a wooden spoon. Coat the cake tin with coconut oil and add the mixture. Add the remaining walnuts before baking and press them gently inside the cake.
Bake for roughly 45 minutes or until golden. Remove from the oven and allow to rest for 15-30 minutes before removing it from its mould.