Let us compare these two sweets, the polvoron and pastillas de leche.
Polvoron uses flour, sugar, powdered milk and butter as basic ingredients. Pastillas uses powdered milk and condensed milk as basic ingredients. A milk fortified with another milk. Both are solid products. The first is drier, uses butter as binder and crumbles easily to touch. The latter is more moist, uses condensed milk as binder and able to transform its shape according to external pressure. They are both made of powder added with certain binder to retain it shape. Then the same set of ingredients can be used to create either or both products.
I tried using pastillas de leche ingredients to make polvoron and the first. The popular ingredients for making pastillas are:
2 cups powdered milk, skimmed milk or popular commercial brands
1 can condensed milk, 300 ml or 390 g
1/2 cup granulated sugar, for rolling of formed pastillas
To make pastillas de leche: Place condensed milk in a large bowl. Add the powdered milk and mix thoroughly. Set aside for ten minutes. Form to desired shape and size. Roll on sugar and wrap.
The above ingredient amounts and procedure are tested and making mistakes is minimal. Excess milk will result to wet and soft pastillas, too dry otherwise. Follow these instead if in doubt: Place powdered milk in a large bowl. Add condensed milk gradually while mixing. It is ready for molding when very tacky or hard to mix.
To make polvoron: Place powdered milk in large bowl. Add condensed milk gradually while mixing until it can be molded with a strike of polvoron maker. Be careful not to add too much liquid. The polvoron will stick to metal side and removing will be hard. In case of this mistake, add more powder to counteract or forget the polvoron and make pastillas de leche instead.