Add the butter, banana, eggs, milk and flour to the blender.
Blend ingredients on a low speed until the consistency of the batter is smooth.
Heat a little oil in a medium frying pan to a moderate heat, then tip off any excess into a bowl. Pour around 2 tablespoons of batter into the pan, tilting the pan as you pour, until the batter thinly coats the base.
Cook from 30 seconds to 1 minute until golden brown on the underside.
Flip over the pancake and cook the other side until it is golden brown. Slide the pancake out of the pan on to a plate, heat a little more oil or butter and cook the remaining pancakes one at a time in the same way.
TIP: To keep the cooked pancakes warm while you're preparing the rest, place on a baking sheet in a 100°C oven until you're ready to serve.
Add the raspberries, blueberries and water in a saucepan.
Bring mixture to the boil and cook for 5 minutes, stirring frequently to prevent the bottom from burning.
Lower the heat and allow the mixture to simmer, reducing until it thickens up.