Preheat your oven to 350°F (175°C). Grease two 9-inch round cake pans and line them with parchment paper.

In a medium bowl, whisk together the cake flour, baking powder, baking soda, and salt.

In a large bowl, beat the butter and sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the lemon zest, lemon juice, and vanilla extract. Gradually add the dry ingredients, alternating with buttermilk, beginning and ending with the flour mixture. If using, add a few drops of yellow food coloring for a vibrant hue.

Divide the batter evenly between the prepared pans and smooth the tops. Bake for 28-30 minutes or until a toothpick inserted into the center comes out clean. Let the cakes cool in the pans for 10 minutes before transferring them to a wire rack to cool completely.

While the cakes cool, beat the cream cheese and butter together until smooth. Gradually add powdered sugar, mixing until creamy. Stir in vanilla extract, lemon juice, and lemon zest for a bright, tangy flavor.

Place one cake layer on a serving plate and spread a layer of frosting on top. Place the second cake layer over it and frost the top and sides. For a smoohfinish, use an offset spatula.