Preheat the oven to 350°F (175°C).
Prepare a 9x13 inch baking pan by greasing and lining it with parchment paper.
In a large mixing bowl, cream the softened butter and sugar together until light and fluffy.
Add the eggs, one at a time, mixing well after each addition.
Mix in the vanilla extract until fully blended.
In another bowl, whisk together the flour, baking powder, baking soda, and salt.
Gradually add the dry mixture to the wet mixture, alternating with the milk.
If desired, add gel food coloring until the batter reaches your desired pink shade.
Pour the batter into the prepared baking pan and smooth the top.
Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
Allow the cake to cool in the pan for 10 minutes before transferring it to a wire rack.
Prepare the frosting by beating the softened butter and powdered sugar together until fluffy.
Mix in the vanilla extract and milk until the frosting is smooth.
Spread the frosting evenly over the cooled cake.
Cut the cake into squares and serve.