Set the oven temperature to 350°F (175°C).
An 8-inch square baking pan may be lined with parchment paper or greased and floured.
Combine the dry ingredients:
Sift the flour, baking powder, and salt in a medium-sized basin. Put aside.
Cream Butter and Sugar: Beat the butter and sugar in a large basin with an electric mixer for three to four minutes, or until the mixture is light and fluffy.
Add the vanilla and eggs:

One egg at a time, adding and beating well after each addition. Add the vanilla essence and stir.
Mix with Dry Ingredients and Milk: Using the dry ingredients first and last, alternately add the dry ingredients and milk to the butter mixture. Blend until barely mixed.
Prepare the Cake:
Using a spatula, level the top of the batter after pouring it into the prepared pan.

When a toothpick put into the middle comes out clean, bake for 25 to 30 minutes.
Take out of the oven and let it to cool in the pan for ten minutes before transferring it to a wire rack to finish cooling.
Prepare the Frosting:
Beat the butter until it becomes smooth for the icing. Add the powdered sugar gradually while beating until frothy and light.
Pour in the milk and vanilla essence, using additional sugar or milk as necessary to get a smooth, spreadable consistency.
Frost the Cake: After the cake has cooled fully, evenly coat the top with icing.
Cut into squares and proceed to serve. For a unique touch, garnish with edible flowers or sprinkles.