Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking dish with butter or cooking spray.

In a large bowl, cream together the butter and sugar until light and fluffy. This should take about 2-3 minutes with an electric mixer.

Add in the eggs one at a time, mixing well after each addition. Then, stir in the vanilla extract.

In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.

Gradually add the dry ingredients to the wet ingredients, alternating with the milk. Start and end with the dry ingredients, and mix well after each addition.

Pour the batter into the prepared baking dish and smooth the top with a spatula.

Bake the cake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

Let the cake cool in the pan for 10-15 minutes, then transfer it to a wire rack to cool completely.

Once the cake is cooled, you can frost it with your favorite frosting recipe, or simply sprinkle it with powdered sugar and serve.