Preheat the oven to 350°F (175°C), and prepare an 8x8-inch baking pan by greasing it or lining it with parchment paper.
In a large mixing bowl, cream together the softened butter and sugar until light and fluffy, about 3-4 minutes.
Add in the eggs, one at a time, mixing well after each addition. Stir in the vanilla extract.
In a separate bowl, whisk the flour, baking powder, and salt together to combine.
Gradually add the dry mixture to the wet mixture, alternating with the milk, starting and ending with the flour mixture.
Add a few drops of pink food coloring and mix until you reach your desired shade.
Pour the batter into the prepared baking pan and smooth the top with a spatula.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Once the cake is done, remove it from the oven and allow it to cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.
Cut the cooled cake into squares and serve or frost as desired.