Mix together sugar and cinnamon powder together in a bowl. Set aside.
Take glutinous rice flour, flour, baking soda, salt, sugar, butter in a bowl. Add hot water little by little and moisten the flour. Once the flour is moistened. Knead it well and set aside for 5 mins. Now take small portion of dough and roll it into a smooth ball.
Heat oil for frying. Don't heat it too much. Drop the balls into the oil and mix it gently using a wooden spoon so the doughnuts don't stick in the bottom or to each other. Fry on medium low heat for 3 to 5 mins. Once the doughnuts are fried, remove it and drain on some paper towel.
Take each doughnuts and coat it in cinnamon sugar. Enjoy immediately.
