Step 1: Preheat the Oven

1. Preheat your oven to 350°F (175°C). Grease and line an 8×8-inch baking pan with parchment paper.

Step 2: Make the Sponge Cake

1. In a bowl, sift together the flour, baking powder, and salt. Set aside.
2. In a large mixing bowl, cream the softened butter and sugar together until light and fluffy.
3. Beat in the eggs one at a time, followed by the vanilla extract.
4. Gradually add the dry ingredients to the butter mixture, alternating with the milk. Mix until just combined and smooth.

Step 3: Bake the Cake

1. Pour the batter into the prepared baking pan and smooth the top.
2. Bake in the preheated oven for 25–30 minutes, or until a toothpick inserted into the center comes out clean.
3. Allow the cake to cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely.

Step 4: Cut and Coat the Lamingtons

1. Once the cake is completely cool, cut it into squares (about 2 inches).
2. Place the raspberry jam in a shallow bowl. Dip each square of cake into the jam, ensuring all sides are coated.
3. Roll the jam-coated cake squares in desiccated coconut until fully covered. Place on a wire rack to set.

Step 5: Serve

1. Serve the Raspberry Lamingtons at room temperature. They can be stored in an airtight container for several days.