Preheat your oven to 350 degrees F (180 degrees C). Butter, or spray with a nonstick cooking spray, the bottom and sides of an 8 inch (20 cm) square cake pan. Then line the bottom of the pan with parchment paper

In a large bowl sift or whisk together the flour, baking powder, and salt.

In the bowl of your electric mixer, or with a hand mixer, beat the butter until soft. Add the sugar and beat until light and fluffy (about 2-3 minutes). Add eggs, one at a time, beating well after each addition.

Add the vanilla extract and beat until combined. With the mixer on low speed, alternately add the flour mixture (in three additions) and milk (in two additions), beginning and ending with the flour

Spread the batter into your prepared pan and smooth the top with the back of a spoon or an offset spatula. Bake in preheated oven for about 30 - 35 minutes, or until a toothpick inserted in the center of the cake just comes out clean.

Cool the cake in the pan, placed on a wire rack, for about 10 minutes Once the cake has completely cooled cut into 16 - two-inch (5 cm) squares

Chocolate Frosting: Place the powdered sugar, cocoa powder, butter and milk in a heatproof bowl placed over a saucepan of simmering water. Stir the mixture until it becomes smooth and of pouring consistency.

To assemble Lamingtons: Place the coconut on a large plate. One at a time, dip the squares of cake into the chocolate frosting and then roll the cakes in the coconut.