Preheat the oven to 350℉. Spray a 8-inch cake pan with baking spray. Line the bottom of the pan with a parchment circle and spray again. Set aside.
In a medium bowl, sift the flour, baking powder, baking soda, and salt. Set aside.
1 3/4 cup All-purpose flour, 1 tsp Baking powder, 1/2 tsp Baking soda, 1/2 tsp Salt
Using a mixer in a large bowl, beat the butter, oil, and sugar on high speed for 2 minutes. It will become fluffy and pale in color.
1/3 cup Unsalted butter, 2 TBSP Oil, 3/4 cup White granulated sugar
Add in sour cream, lemon zest, lemon juice, and eggs. Mix on medium speed until combined. Make sure to scrape the bowl using a baking rubber spatula.
1/4 cup Sour cream, 2 TBSP Lemon zest, 2 TBSP Lemon juice, 2 Large eggs
Add in the dry ingredients and buttermilk, mix on low speed until just combined. Take off the mixer and scrape the bowl.
1/2 cup Buttermilk
Spread the cake batter into the cake pan. Bake for 25-30 minutes. Bake until a toothpick inserted comes out clean.
Let the cake sit in the hot pan for 10 minutes before transferring to a cooling rack. Cool completely before decorating.