Preheat the oven to 350°F. Spray 2, 8-inch round cake pans with nonstick cooking spray. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, add the butter. Cream until pale in color (about 2 minutes).
Add the sugar to the creamed butter and mix for an additional 1-2 minutes, or until light and fluffy, scraping the sides of the bowl as needed.
Add the eggs, one at a time, making sure each egg is incorporated before adding the next one.
In a separate bowl, whisk together the flour, salt, and baking powder.
In another bowl, combine the milk, oil, and vanilla.
With the mixer on low speed, alternate between adding the flour mixture and the milk mixture to the butter mixture, beginning and ending with the flour mixture. Mix until the ingredients are fully incorporated, adding your desired amount of food coloring.
Remove the bowl from the stand mixer.
Pour the batter equally between the two cake pans. Bake the cakes for 30-35 minutes, or until an inserted toothpick comes out clean.
Allow cakes to cool in the pans for 10 minutes before turning them over onto a wire rack to cool completely.