In a large mixing bowl, combine the all-purpose flour, rice flour, sugar, salt, and baking powder. Mix well to ensure all the ingredients are evenly distributed.

Gradually pour the warm water into the dry mixture. Stir everything together until you have a smooth, cohesive dough. If the dough feels too sticky, sprinkle a little more all-purpose flour.

Lightly flour your workspace, and knead the dough for about 5 minutes until it's smooth and elastic.

Divide the dough into small balls, approximately the size of a golf ball. Flatten each ball slightly with your palm to shape it into a disc.

Allow the discs to rest on a floured surface for about 15 minutes. This will help them rise a bit during frying.

In a large, deep skillet, heat enough oil for frying over medium heat. You can test the oil by dropping a small piece of dough into it; if it bubbles and rises, it's ready!

Carefully place a few discs into the hot oil, frying until they turn golden brown, usually about 3-4 minutes on each side. Make sure not to overcrowd the pan.

Once golden brown, remove the fried donuts with a slotted spoon and drain them on paper towels. While still warm, sprinkle sesame seeds on top for that extra crunch!

Let them cool slightly, and enjoy your Vietnamese donuts fresh out of the fryer!