Preheat oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.

In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt.

In a separate bowl, whisk together buttermilk, oil, eggs, vanilla, and pink food coloring.

Gradually add wet ingredients to dry ingredients, mixing until just combined. Be careful not to overmix.

Pour batter evenly into prepared cake pans.

Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

Let cakes cool in pans for 10 minutes before inverting onto a wire rack to cool completely.

In a large bowl, beat butter until smooth.

Gradually add powdered sugar, beating until combined.

Beat in milk, vanilla, and pink food coloring until smooth and creamy.

Once cakes are cool, level the tops if necessary. Place one cake layer on a serving plate and frost with a layer of frosting. Top with the second cake layer and frost the top and sides of the cake.