Peel the bananas and put them on a big plate. Cut one banana in half lengthwise and put back on the plate. Put about 1 tablespoon coconut oil in a nonstick skillet over medium-high heat. When the oil is warm, put the banana halves in and fry for 2-3 minutes. Flip gently and fry until lightly golden. Set a side.
Preheat the oven to 360°F/190°C and line a loaf pan with baking paper.
Mash the other two bananas with a fork and set a side.
Put the coconut oil and sugar in a medium bowl and whisk vigorously to combine. Stir in the coconut milk and whisky. Add the eggs and whisk everything gently to combine.
Add the flour, baking powder and salt and stir gently with a spatula until the batter is smooth. Add the mashed bananas and chocolate chunks and stir gently until well combined.
Put the fried bananas over the batter and bake for about 30 - 40 minutes, until the cake is golden brown.
The cake is ready when a toothpick inserted in the center of it comes out clean.
You can skip the banana frying and just put the halves over the batter as is but maybe sprinkle them with sugar so they caramelize in the oven. It's okay if the banana breaks in half. Put it how ever you feel like.