Preheat your oven to 170°C (340°F) and grease a square pan, lining the bottom with parchment paper.

In a mixing bowl, cream together the softened butter and sugar until pale and fluffy.

Add the eggs, one at a time, mixing until smooth after each addition.

Stir in the vanilla extract.

In another bowl, sift the flour, baking powder, and salt.

Fold half of the dry ingredients into the batter, then add the milk and stir until blended.

Fold in the remaining flour until the batter is smooth.

Transfer the batter to the prepared pan and level the top.

Bake in the preheated oven for 35 to 45 minutes, or until a skewer comes out clean.

Allow the cake to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.