Preheat your oven to 325 degrees.
Combine the flours and sit it to the side. Then, using a hand or stand mixer, mix the butter, shortening and sugar together on medium speed until light, and fluffy (approximately 5 minutes).
Add the vanilla flavoring.
Then, add the eggs to the bowl one at a time, mixing only until combined before adding the next egg. Using a spoon or spatula, scrape down the sides of the bowl.
Slowly mix in the flour, alternating with sour cream, beginning and ending with the flour.
Spray a 12-cup bundt pan with baking spray. Pour the batter into the pan and smooth the top of the batter.
Place your pound cake into your preheated oven and bake for about an hour and 15 minutes (or longer if needed). The cake is done once a toothpick inserted into the middle of the cake comes out clean.
Remove the cake from the oven and allow it to cool for about 10-15 minutes before removing it from the pan.
Remove the cake from the pan. Allow it cake to cool, then serve and enjoy!