Preheat the oven to 325 degrees, spray a 10 tube pan with non stick spray and set aside. In a small bowl, mix together the flour, pandegliangeli, vanillina and salt, set aside. In a large bowl, whisk together the oil, butter and sugar until very creamy, add the eggs and continue to mix until you have a nice thick and pale color. Add the milk and mix it in quickly, add the flour mixture and mix it all together until its incorporated but dont over mix. Pour 2/3 of the batter into the prepared pan and set aside. Add the cacao powder to the reserved 1/3 of the batter and mix it all together so you have a smooth chocolaty batter. Spoon the chocolate mixture all over the top of the cake batter and using a butter knife, run it all threw to slightly mix the batter together but dont stir the two batters completely!Bake the cake for about 1 hour and 15 minutes. Allow to cool completely before inverting onto a platter.