Preheat the oven to 325 degrees F (165 degrees C). Lightly grease a 9x13-inch baking pan.

Mix together milk, rice flour, sugar, canola oil, and baking powder in a large bowl until combined. Stir in beaten eggs until incorporated. Pour mixture into the prepared baking pan.

Drop small spoonfuls of red bean paste into batter, 1 to 2 inches apart; make sure red bean paste is covered by batter. Sprinkle with sesame seeds.

Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 55 minutes. Cool in the pan for 10 minutes before removing to cool completely on a wire rack.