Cut the peeled banana lengthways once and place it on a microwave-safe plate.
Then you put 1 teaspoon (3g) of baking cocoa in a small bowl and very carefully add tap water drop by drop until you have a slightly runny chocolate sauce. Add a teaspoon (5g) of agave syrup to sweeten it.
Now the banana is poured with the chocolate sauce and warmed in the microwave for a few seconds at medium temperature.