Start by adding the hot water to the glutinous rice flour, mix well, and knead until it's well blended. The rice flour mixture should be smooth. Set aside.

Cut the dough into 6 even small pieces and roll them into small, flat circles. Put the red bean filling into the center of the dough skin, about 1 tablespoon of filling. Then wrap the skin around the filling and shape it into a ball. Use a rolling pin to gently flatten it to a thick pancake shape. (About 1/4 inch thick).

Add a little bit of cooking oil to a non-stick pan and add the uncooked red bean cake on medium-low heat. Flipping them over to cook both sides (about 4 minutes per side, watch out for burning). Pan fry until it's light golden brown.

First, soak the red beans in water overnight or at least 3 hours ahead.

Drain soaked red beans and wash them again, then add clean water to cook the red beans.

Bring red beans and 5 cups of water to a boil and simmer it for one hour on medium-low heat. (If you are using a pressure cooker to speed up the process, check the manual for the exact cooking time)

Smash the cooled-down red beans into a paste with a spatula. Add red beans, sugar, and oil into a food processor or blender, and blend until a creamy texture is achieved or the desired consistency. Taste and adjust the amount of sugar if needed. Keep blending until it forms a smooth batter.

In a non-stick saucepan, add one tablespoon of butter, and heat the filling mixture until it's firmed up. Turn off the heat and remove from it the stove immediately. Refrigerate cooked red beans for at least 2 hours before making a cake.