Soak the chia seeds with the water for 30 minutes. Add the sugar and whisk using an electric mixer for around 10 minutes until fluffy.
Turn the mixer to a low speed setting and gradually add the oil and mix until well incorporated.
Sieve in the flour, the coco powder and the baking powder and fold through trying not to mix too hard.
Spoon into a pre-lined baking foils, add a spoonful of peanut butter and place into a preheated 150ºC/300°F/gas mark 2 oven for 10 minutes.
Once baked, cool slightly before serving.