Heat the milk, vegetable oil and sugar in the microwave for about 2 minutes just until the sugar has melted. Do not let it come to a boil. Let it cool to lukewarm and then sprinkle the yeast on top and let it sit for 1 minute. Add 8 cups of flour, stir until just combined. Cover with a towel and set aside in a warm place for an hour.
Remove and add the baking powder, soda, salt and remaining flour. Stir thoroughly to combine.
To assemble the rolls, punch down the dough and divide in half. Place one half on a floured baking surface. Roll into a large rectangle about 24 X 10 inches. Cover with 1/2 of the melted butter using your fingers to spread it out. Generously sprinkle cinnamon and 1/2 cup of brown sugar and 1/2 cup of white sugar over the butter. If you are adding raisins or nuts, sprinkle them over now.
Roll the rectangle tightly toward you, using both hands to keep the roll tight. Pinch the seam together when you have finished rolling. Cut into 11/2 inch slices and place in pie pans or a rimmed baking sheet that has been greased with butter. Do not overcrowd the rolls. Repeat with remaining dough.
Preheat the oven to 375º and let rolls rise while the oven is preheating, about 20 minutes. Bake for 13-17 minutes, until golden brown.
Icing: In a large bowl, whisk together the powdered sugar, melted butter, milk and salt, then add the vanilla. Whisk until very smooth. It should be thin but pourable. If it is too thick, add additional milk. When the rolls come out of the oven, drizzle the icing over the top.