In a stand mixing bowl, add in 4 cups flour, the rest of the sugar and salt. With dough hook, turn the mixer on low and stir well. Once the milk mixture has bloomed, leave the mixer on low speed and slowly add the mixture. Once it has started to combine, add in egg and oil. Once the ingredients are combined, turn the mixer up to medium low and allow to knead for about 5 minutes. The dough should be sticky but should be pulling away from the sides and bottom of the bowl. If this is not happening, add in more flour about 1 TBS at a time. When done, allow the dough to rest in the bowl for about 5 minutes while you make the filling.