Add sweet rice flour into a large bowl. Measure out 1 cup of water (You will use slightly less than a cup). Slowly add water into the flour in 4 to 5 pours, and stir with a fork until the water is fully incorporated with the flour. There should be no dry flour left, and the flour should start to have the texture of dough - soft but not runny. If the dough gets too soft and becomes difficult to shape, add more rice flour, a tablespoon at a time. Use your hand to press and knead the dough a few times, until the texture becomes consistent (* see footnote). The dough should be soft and easy to shape. When you lift the dough from the bowl, it should slightly stick to the bottom of the bowl.
Dust a working surface with rice flour and transfer the dough onto it. Divide the dough in half. Roll the dough with both hands to shape it into a long, even rod. Divide the dough equally into 6 pieces. Shape each piece into a round ball and set aside.
To make the cake, place one rice dough ball in your palm and use the other hand to gently press it into a round, flat piece (it’s very easy to shape, so you won’t need a rolling pin), about 6 centimeters (2.5 inches) in diameter, 6 millimeters (1/4 inch) in thickness.
Scoop about 2 tablespoons of red bean paste and shape the paste into a ball. Place the ball of bean paste in the center of the round dough. Pinch the edges of the dough together to completely enclose the bean paste. When the cake is shaped like a ball, gently use your palm to press it, until it is shaped like a pancake, about 6 centimeters (2.5 inches) in diameter and 1.2 centimeters (1/2 inches) in thickness. Spread 1 tablespoon of sesame seeds onto the working surface, place the cake on top of them, and gently press. Shake off the extra sesame seeds, flip the cake, and press the other side onto the seeds. Craft the rest of the cakes in the same manner.
Heat 1 teaspoon of vegetable oil a non-stick skillet over medium heat. When the oil is hot, turn to medium low heat and place 4 cakes into the skillet. Cook until the bottom of the cake turns golden brown, after 2 to 3 minutes. Flip and cook the other side. Transfer the cakes to a large plate to cool. Cook the rest of the cakes in the same manner.
Serve the rice cakes warm.