Preheat the oven to 350°F (175°C) and grease and flour two 9-inch round cake pans.
In a large bowl, cream together the butter and sugar until light and fluffy.
Add eggs one at a time, beating well after each addition.
Stir in the vanilla extract.
In a separate bowl, sift together the flour, baking powder, and salt.
Gradually add the dry ingredients to the creamed mixture, alternating with milk.
Mix just until combined; do not overmix.
Pour the batter evenly into the prepared pans.
Bake for 30-35 minutes or until a toothpick inserted comes out clean.
Let the cakes cool in the pans for 10 minutes, then turn out onto wire racks to cool completely.