Preheat your oven to 350°F (175°C).
Grease two round 9-inch cake pans with butter and line with parchment paper.
In a large mixing bowl, cream together unsalted butter and granulated sugar until light and fluffy.
Beat in eggs one at a time, followed by vanilla extract.
In another bowl, whisk together cake flour, baking powder, and salt.
Gradually add dry mix to wet ingredients while alternating with milk until smooth.
If desired, divide batter into bowls and add food coloring until achieving desired shades.
Pour each colored batter into prepared pans.
Bake in preheated oven for 25-30 minutes or until a toothpick inserted comes out clean.
Let them cool completely before frosting.