Preheat the oven to 180 C / Gas 4. Grease a small loaf tin.
Combine coconut oil, eggs and vanilla extract in a large bowl; whisk well to combine. Add flour, sugar, bicarbonate of soda, cinnamon and salt. Stir well until combined. Fold in mashed bananas, pineapple and coconut; stir until just blended. Pour mixture evenly into the prepared loaf tin.
Bake in the preheated oven until a skewer inserted into the centre comes out clean, about 1 hour. Cool in the tin for 10 minutes. Remove to a wire rack to cool completely.