Beat butter on medium speed, gradually add the sugar and vanilla and beat for 3-4 minutes more. Add eggs, one at a time beating well after each addition. Sift together flour, baking powder and baking soda, and add them on low speed. Add milk and mix to combine. Do not over beat. Pour into the prepared pan and bake for 30 minutes or until a toothpick inserted in the center comes out clean. Let cool and serve.