Put sifted flours into the bowl of a food processor. Add in sugar, milk powder, salt and yeast. Stir in corn oil, butter and water. Process with a dough hook for four to five minutes until a soft dough is formed. Set aside, covered, for 15-20 minutes.
Grease two pizza trays lightly with corn oil. Turn out dough on to a lightly floured tabletop. Knead by hand for one to two minutes. Divide the dough into two equal parts.
Roll out dough to fit the prepared pizza trays and brush the surface lightly with a little corn oil. Bake dough in preheated oven at 180ºC for 10 minutes.