Preheat the oven to 180°C.
In a small bowl, mix the coconut milk with the lime juice and set aside for a few minutes.
Mash or blend the bananas until smooth, then transfer to a mixing bowl. Add the egg and oil and mix well.
Stir in the coconut flour, coconut sugar and gluten-free flour.
Pour in the coconut milk mixture and gently mix until you have a smooth, thick but pourable batter. If it feels too thick, add a little more coconut milk.
Divide the mixture between two small silicone bundt moulds.
Bake for 15–20 minutes, until golden and set.
Leave the cakes to rest in their moulds for about 10 minutes, then turn them out onto a wire rack to cool completely.
Serve as they are, or topped with a sprinkle of shredded coconut or a drizzle of date syrup.