Preheat your fan oven to 160°C (325°F) or 175°C (350˚F) if you’re not using a fan oven. Grease and line with parchment paper 8x8 inch (20x20 cm) square tin.
In a medium bowl sift together flour, baking powder and salt. Whisk until combined and set aside. In a measuring jug combine whole milk and vanilla extract. These are your wet ingredients.
In a bowl of a stand mixer fitted with a paddle attachment, cream the butter, vegetable oil and sugar on a medium-high speed until paler in colour. (approx. 2-3 min) Stop the mixer and scrape down the bowl.Turn the mixer to medium-low speed and add eggs one at a time – making sure it’s fully incorporated after each addition. Stop the mixer and scrape down the bowl.
Add your dry and wet ingredients, alternating between one another, starting and finishing with dry ones. (3 additions of dry and 2 of wet ingredients)Pour the batter in prepared tin and bake for 25-35 minutes or until skewer inserted in the middle comes out with few moist crumbs. Do not overbake it.
Once it's done, let the cake cool for 10-15 minutes on a wire rack before removing it from the pan to cool completely. The cake will continue to cook in the pan, so it’s important that the skewer is not entirely clean. Otherwise, your cake will overbake and that will cause dryness.
for strawberry jam
Cook strawberries with sugar and squeeze of a lemon juice over a medium-high heat until it reaches boiling. Using a potato masher, mash strawberries. Turn the heat down and let it simmer for approx. 15 minutes or until it thickens. It's better to be thicker than looser, the plan is to lose a lot of water content and have concentrated flavour. I like to have small strawberry pieces here and there, but if you want your jam to be extra smooth then strain it through a sieve or blitz with a hand blender. Cover it with cling film and leave it to cool in the fridge.
for the chocolate icing
Make the chocolate icing by melting together the chocolate, butter and milk over a bain maire (a heatproof bowl set over a pan of simmering water). Remove the bowl from the pan of simmering water when smooth, then whisk in the powdered sugar and cocoa powder you have previously sifted to get rid of lumps.In the very end add boiling hot water. You want to get just the right consistency, not too thin to make the lamingtons soak too much of liquid and become mushy, and too thick.
Once your cake is cold, trim the edges with a serrated knife and cut the cake horizontally using the same knife or a cake leveler. Fill the cake with strawberry jam and then cut it into 16 or more squares. Then put it in the freezer for 15 minutes to become firm, which will make the dipping in chocolate part easier.
Pour the dessicated coconut onto a large deep plate.Using two forks, dip a piece of sponge into the chocolate icing mixture, making sure that all sides are coated, and allow any excess icing to drain off. Then roll the chocolate-coated sponge in dessicated coconut and place the lamington on a wire rack to dry. Repeat with the remaining sponge pieces. If the icing mixture becomes too thick, whisk in some milk or water to thin it out. Let the lamingtons set on a wire rack for about an hour or put them in the fridge to speed up setting process.
If you don’t have a stand mixer, you can use a hand mixer.
Not all ovens are the same. I suggest to check the cake at 25 min mark and then adjust the baking time accordingly. Get to know your oven!
If you still don’t own one, I advise you to buy a kitchen scale – they’re cheap and easy to use, and always guarantee the same results in baking!
Lamingtons are best eaten at room temperature. You can keep them in a fridge, in an airtight container or wrapped in cling film, but take them out of it at least half an hour before serving.
You can cut the cake into more squares, it depends how big or small you want them to be. If you wish to make lamingtons without filling, you can skip the freezing step before dipping into chocolate icing!