Preheat your oven to 350°F (180°C) and grease and line an 8x11 inch (20x30cm) rectangular baking pan with parchment paper.

In a large bowl, cream the softened butter and granulated sugar together using an electric mixer until the mixture is pale and fluffy, about 3 minutes.

Add the eggs one at a time, beating well after each addition, then stir in the vanilla extract until fully combined.

Sift the flour and baking powder together, then gently fold half into the butter mixture, followed by half the milk, repeating until the batter is smooth.

Pour the batter into the prepared pan and bake for 25 minutes, or until the cake springs back when lightly touched and a toothpick comes out clean.

Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely (this prevents crumbling when cutting).

Once cool, trim the edges of the cake and cut it into 12 even squares.

Slice each square in half horizontally, spread a teaspoon of raspberry jam on the bottom half, and replace the top to create a sandwich.

To make the icing, whisk the icing sugar, cocoa powder, melted butter, and boiling water in a bowl until smooth and glossy.

Place the desiccated coconut on a separate plate or shallow bowl.

Using two forks, dip each jam-filled cake square into the chocolate icing, ensuring it is coated on all sides, then let the excess drip off.

Immediately roll the coated cake in the desiccated coconut until evenly covered, pressing lightly if necessary to help it stick.

Place the finished lamingtons on a wire rack to set for at least 15 minutes before serving with a fresh cup of tea.