Make the Dough: Whisk together the egg, oil, soy milk, and sugar in a bowl until well combined. Add the rice flour and baking powder and mix until smooth.
Shape the Donuts: Take small portions of the dough and roll them into loose balls. For a classic donut shape, gently flatten each ball and poke a hole in the center.
Fry the Donuts: Heat oil in a frying pan over medium heat. Add the donuts and cook until golden brown. Transfer them to a wire rack or a paper towel-lined plate to drain the excess oil.
Notes
If the dough is too firm, add a bit more soy milk to soften it.
For a classic donut shape, gently flatten each ball and poke a hole in the center.
You can enjoy them as is or dust them with powdered sugar or cinnamon sugar for a sweet finish.