Step 1: Put the flour, white sugar and yeast in the crust ingredients (200g flour, 10g sugar, 3g yeast, 105g water) into a basin, slowly pour in the prepared water, and pour in the prepared water slowly. Add while stirring with chopsticks. When no dry powder is visible, knead into smooth flour with your hands.

Step 2: Ferment at room temperature until doubled in size.

Step 3: After washing the yam, steam it in a steamer for about 25 minutes, take it out and let it cool.

Step 4: Put the peeled yam into the breaking machine cup.

Step 5: Connect the wall breaking machine to the power supply and select the grinding function.

Step 6: The yam puree is completed in about 35 seconds.

Step 7: Put butter in a non-stick pan and slowly melt over low heat.

Step 8: Add the yam paste and stir-fry slowly over low heat.

Step 9: Fry for about 15 minutes. When the water in the yam paste is almost dry, add sugar and coconut and stir-fry evenly.

Step 10: After the fermented dough is smooth, divide it into 5 small portions.

Step 11: Take one of the doughs, roll it into a round dough, and put the fried yam paste in the center of the dough.

Step 12: Knead the edges and make the wrinkles as small as possible. Place the wrapped pie flat on the chopping board, tap it a few times, and use a rolling pin to gently roll it into a round pancake.

Step 13: Heat the electric baking pan and brush it with a little oil, put the pie embryo in and bake until both sides are golden and remove from the pan.