Preheat oven to 350 degrees. Brush your bundt pan with the melted butter. Then sprinkle in the flour and tap to coat the pan. Set this aside. In a small bowl, combine the all-purpose flour, whole wheat pastry flour, baking powder, and salt. Set this aside.
In a bowl of a stand mixer or hand mixer, add the butter, oil, and granulated sugar. With beaters, mix until the batter is light and fluffy, about 3 minutes. Add in the eggs, one at a time, until they are all mixed in.
Add in the vanilla, sour cream, and orange zest. This time only mix to combine.
Next up is the flour mixture. Add this in and mix only until it is combined. Do not overmix at this point.
Last in is the cranberries. I like to mix these with a rubber spatula. Pour into your prepared pan and then into the oven.
Bake for 60 minutes. Check with a toothpick or instant-read thermometer. Remove from the oven and allow this to cool for 15-20 minutes in the pan. Then carefully invert onto your cooling rack.
I do this by putting the rack on top of the cake, then turning it over while still holding the cake to the rack.