In a bowl place the gluten-free flour mix and the cocoa powder.
In another bowl, mix the water, sugar and coconut oil and pour over the flour.
Now add the mashed banana. Add the baking powder, baking soda and apple cider vinegar over the baking soda.
Mix well. Distribute in cupcake moulds, and decorate with dark chocolate chips, if you like.
Bake in a preheated oven for approximately 25 minutes at 180°C.
Make sure the muffins are baked!