Rinse the rice for couple of times; soak the rice in water overnight. After that, drain the rice. Blend the drained rice along with butter and sugar in a blender adding water until the mixture reaches to the consistency in-between of pancake and churros batter. Meanwhile, heat 1 liter of sunflower oil in a deep cast iron pan. Place a metal bowl in the middle of pan. Pass the batter through a funnel around the corners of the pan making it round shaped while frying. Take the fritter out when the batter turns golden. Repeat the same process until the end.