Preheat oven to 350°F. Spray two 8-inch cake pans with non-stick baking spray. Line the bottom of the cakes with 8-inch parchment paper circles and spray again.
In a medium bowl, sift the flour. Add the baking powder, baking soda, and salt. Set aside.
3 1/2 cups All-purpose, 2 tsp Baking powder, 1 tsp Baking soda, 1 tsp Salt
Using a mixer, beat the butter, oil, and sugar. Beat these on high speed for 3 minutes for it to get light and fluffy. Next, add the vanilla and sour cream.
3/4 cup Unsalted butter, 1/4 cup Oil, 1 1/2 cups White granulated sugar, 1/4 cup Sour cream, 1 TBSP Pure vanilla extract
Add the eggs one at a time and mix on medium.
4 Large eggs
Add 1/3rd of the dry ingredients and half of the buttermilk and mix on low speed. Then, add another 1/3rd of the dry ingredients and the rest of the buttermilk. Finish with the rest of the dry ingredients.
1 cup Buttermilk
Pour the cake batter evenly between the cake pans.
Bake for 27-30 minutes until a toothpick inserted comes out clean. Let the cakes sit in the hot pans for 10 minutes. Then, cool on a cooling rack. Cool completely.