Steps
1. Preheat the oven to 350°F (175°C).
2. In a small saucepan, melt the butter over low heat.
3. Mash the banana in a bowl and add it to the melted butter.
4. Dissolve the instant coffee in 1 tablespoon of hot water and add it to the banana mixture.
5. Separate the egg yolks from the whites and add the yolks to the banana mixture. Mix well.
6. In a separate bowl, beat the egg whites until stiff peaks form.
7. Gently fold the beaten egg whites into the banana mixture.
8. Pour the mixture into individual ramekins or a baking dish.
9. Peel and slice the mango, then arrange the slices on top of the banana mixture.
10. Bake in the preheated oven for 20-25 minutes, or until the top is golden brown.
11. Serve warm or chilled.