Preheat the oven to 350℉. Spray three 8-inch cake pans with baking nonstick spray. Line the bottoms with parchment paper circles and spray again.
In a medium bowl, sift the flour, baking powder, baking soda, and salt. Set aside.
In a large bowl using a mixer, beat the butter, oil, and sugar on high speed for 2 minutes it will be fluffy and pale in color.
Add in the lemon zest, lemon juice, sour cream and eggs. Mix on medium speed until combined. It will look split due to the acid in the lemons, but this is normal.
Add in the dry ingredients and buttermilk and mix on low speed until just combined. This will be a thick cake batter.
Pour the cake batter evenly between the cake pans. Bake for 22-26 minutes. Bake until a toothpick inserted comes out clean.
Let the cakes sit in the hot pans for 10 minutes before transferring to a cooling rack. Cool cakes completely before decorating.