Preheat your oven to 350°F (175°C) and grease a baking pan.
In a bowl, whisk together the flour, baking powder, and salt.
In a separate bowl, mix the melted butter, sugar, eggs, vanilla extract, and milk until smooth.
Gradually add the dry ingredients to the wet mixture, stirring just until combined. Do not overmix.
Pour the batter into the prepared pan and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
Let the cake cool before slicing. Serve plain, dusted with powdered sugar, or topped with your favorite glaze.