Preheat the oven to 350°F (175°C).

Grease your baking dish with butter or cooking spray.

In a mixing bowl, combine the flour, baking powder, and salt.

In another bowl, beat the softened butter and sugar together until light and fluffy.

Mix in the eggs one at a time, followed by the vanilla extract.

Gradually add the dry mixture to the wet ingredients, alternating with the milk.

Pour the batter into your prepared baking dish.

Bake for 30 minutes, or until a toothpick comes out clean.

Let it cool slightly before serving.