Preheat your oven to 350°F (175°C). Grease and flour a 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. Gradually add to the creamed mixture alternately with milk, beating well after each addition.
Pour 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.