Preheat oven to 400 F
Place flour on baking sheet and bake for 30 minutes; stir flour every 5-10 minutes. To define the flour is cooked or not, you can see how the flour changed in color, instead its original white color, it will turn to brown color.
Set aside to cool flour.
Reserve about 1/2 cup cooked flour; for dusting your mooncake mold.
Mix (either with hand or a mixer) half-cooled cooked flour with icing sugar, oil, milk, bits by bits until ingredients form paste/dough.
You can add food essence and/or food coloring while mixing the ingredients.
Dust your mold with reserved cooked flour
Make balls/rolls of the paste and the fillings (red bean and/or chestnut puree); flattened the paste ball and place the filling ball in the middle, close the flattened paste ball, seam to seal, place it into the mold, press with your palm, knock slightly and turn mold over onto a serving plate.
Serve mooncake chilled and enjoy :)