Preheat your oven to 350°F (175°C). Grease and flour your cake pan.
In a mixing bowl, cream together the 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 another bowl, combine the flour, baking powder, and salt. Add this mixture to the creamed mixture alternately with the milk, beginning and ending with the flour mixture. Beat until just combined.
Pour the batter into the prepared pan. Bake for 30 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then turn out onto a wire rack to cool completely.