Preheat the oven to 350°F. Spray three 8-inch cake pans with baking nonstick spray. Line the cake pans with 8-inch parchment paper circles. Spray again.
In a mixing bowl, sift the flour. Add the baking powder, baking soda, and salt. Set aside. Zest the lemons and juice one of the lemons and set aside.
3 ½ cups All-purpose flour, 2 teaspoon Baking powder, 1 teaspoon Baking soda, 1 teaspoon Salt, 3 Large lemons zested, ¼ cup Lemon juice
Using a mixer, beat the butter, oil, and sugar on high speed for 3 minutes. It will be very light and fluffy.
¾ cup Unsalted butter, ¼ cup Oil, 1 ½ cups White granulated sugar
Add the lemon zest, lemon juice, vanilla, and sour cream. Mix on medium until combined. Add the eggs in one at a time and mix on medium until combined.
¼ cup Sour cream, 4 Large eggs, 1 teaspoon Pure vanilla extract
Add ⅓rd of the dry ingredients and half of the buttermilk and mix on low speed. Add another ⅓rd of the dry ingredients and the rest of the buttermilk. Finish with the rest of the dry ingredients. Scrape the bowl using a rubber spatula.
1 cup Buttermilk
Pour the cake batter evenly into the 3 cake pans. Bake for 22-25 minutes. Bake until a toothpick inserted comes out clean.
Let the cakes sit in the hot pans for 10 minutes. Then, transfer to a cooling rack to cool completely.