Preheat oven to 180°C. Grease or line a 12-hole muffin tin with paper liners.
Combine boiling water and Moccona in a large bowl and stir to dissolve.
Add milk, mashed banana, olive oil, sugar, and salt to the bowl. Mix well. Add flour and chocolate, and stir until just combined.
Divide batter into prepared muffin cups. Bake 20 - 22 mins until a toothpick inserted into the centre of a muffin comes out clean.
Cool in tin 2 mins, then turn out onto a rack to cool completely.