Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans.
In a large bowl, cream together the softened butter and sugar until light and fluffy.
Add the eggs one at a time, beating well after each addition.
Stir in the vanilla extract.
In a separate bowl, combine flour, baking powder, and salt.
Gradually add the dry ingredients to the wet mixture, alternating with milk.
Mix just until combined; do not overmix.
Pour the batter evenly into the prepared pans.
Bake in the preheated oven for 25-30 minutes, or until a toothpick comes out clean.
Allow cakes to cool in the pans for 10 minutes, then transfer to wire racks to cool completely.