Heat a medium sized saucepan. Rub the sugar on both sides of the banana. Just press them on the surface of the banana.
Place the halved bananas face down on the hot saucepan and pour the water and brandy. Gently tilt the pan towards the flame to ignite it. It will burn to a beautiful blue flame. If you are using an electric stove, you will have to ignite it with a match stick. Be careful when you do it. Leave the windows open and keep the house ventilated. Don’t place any flammable material around the cooking area. Move the kids away.
Once it has completely burned, increase the heat to caramelize the liquid, about 8-10 minutes or until done. It will make the base of the banana brown and sticky.
Transfer to a clean bowl. Top with scoop of ice cream and ground pistachios. You can add some sticky, gooey speckles of the sauce on top.