Step 1

For the cake: Preheat the oven to 350º.

Step 2

Whisk together the flour, baking powder, baking soda, and salt in a medium bowl.

Step 3

Whisk together the butter, olive oil, and sugar in a large bowl until combined. Add the eggs and whisk for 1 to 2 minutes, until lightened in color. Add the vanilla, buttermilk, lemon zest and juice, and whisk to combine. Add the flour mixture and whisk to combine.

Step 4

Spray 2 8-inch round cake pans with baking spray with flour. (Alternatively: butter and flour the pans). Divide the batter evenly between the prepared pans. Tap the pans a few times each on a kitchen towel on your counter-top to level the surface and remove air bubbles from within the batter.

Step 5

Bake for 28 to 32 minutes or until toothpick inserted into the center comes out with only a few crumbs. Transfer to a cooling rack. Let cool in the pans for 10 minutes, then turn out onto a cooling rack to cool completely, about 1 1/2 hours.

Step 6

For the frosting: Add the butter, cream cheese, and lemon zest to the bowl of an electric stand mixer fitted with the paddle attachment and beat on medium speed until creamy, about 2 minutes. Add the powdered sugar. Beat on low speed until combined. Increase the speed to medium and beat until smooth, about 1 minute. Scrape down the sides and bottom of the bowl. Add the lemon juice and yellow food coloring, if using. Beat until light and smooth, about 2 more minutes.

Step 7

To assemble: Trim the cake layers to make the tops flat and even, as needed. Place 1 cake layer on a cake plate. Spread 1 cup of buttercream over top. Top with the second cake layer and spread buttercream all over the top and sides of the cake.

Step 8

Garnish with white chocolate curls, lemon slices, and/or edible flowers, if you like.