Preheat your oven to 350 degrees and generously grease a loaf pan with baking spray. Optionally line the pan with parchment paper for easy removal. I'm using an 8x4 inch loaf pan, but you can use a larger one as well, it just may take less time to bake.

In a medium bowl, stir together the flour, baking powder, and salt, and set the mixture aside. In a large bowl, beat together the butter, oil, and sugar until smooth and fluffy, about 1-2 minutes. Add in the sour cream, vanilla extract, and one egg- stir until well combined. Then, beat in the second egg.

Add in about 1/3 of the flour mixture and stir until well combined. Then add in about half of the buttermilk and stir to combine. Repeat until all of the buttermilk has been added. On the final addition of the flour mixture, add in your mini chocolate chips as well, and beat the mixture until it's well combined. The batter should be very thick.

Spread the batter into your prepared baking pan evenly. Bake in your preheated oven for 65-75 minutes, or until a cake tester comes out clean. Cool the cake completely in the pan before removing to slice and serve. Enjoy!