Preheat the oven to 180C / 350F / 160C fan forced. Grease and line 2 x 8 inch cake tins with baking paper. Now grease the baking paper.
Sift together the flour, baking powder and salt, mix, then set aside.
Beat together the butter and sugar. Add 2 eggs and beat until incorporated. Add the last 2 eggs and vanilla and beat until smooth (it may look split but that’s ok). Finally add the dry ingredients and mix through with a spatula until just combined.
Bake for 25-27 minutes. Do not open the oven door before 20 minutes or the cakes may sink.
Remove from the oven and allow them to cool in the tins for 5 minutes before turning out onto cooling racks.
Immediately turn the oven down to 140C / 285F / 120C fan forced.
For the meringue
Make sure your oven has cooled to 140C / 285F / 120C fan forced. Grease and line an 8 inch cake tin with baking paper, then grease the paper well with mild vegetable oil.
In a stand mixer, with the whisk attachment (or using a handheld beater), beat the egg whites on high to soft peak stage. About 3-4 minutes.
Sift over the cream of tartar and beat through. Now add the sugar one tablespoon at a time until the egg whites are thick and glossy and at stiff peak stage (another 5-7 minutes).
Once all the sugar is incorporated, test the mixture by rubbing a little between your finger and thumb. It should be smooth. If it is still grainy, keep beating until it is smooth when you test it.
Tip the meringue into the prepared tin and spread out so that it is basically level, but then you can add some waves here and there if you want some added interest.
Place in the oven and bake for 1 hour (see notes). Turn off the oven and wedge open the door and allow the meringue to cool completely in the oven.
Spread most of the curd over one of the cakes.
Whisk the cream until whipped then spread half over the top of the lemon curd.
Top with the second cake, then spread a thin layer of lemon curd over the top (just enough to stick the meringue to the cake. Sit the meringue on top then carefully spread over the remaining cream.
I use a standard Australian 20ml tablespoon (4 teaspoons worldwide)
For best results you should always weigh ingredients like flour and sugar. Kitchen scales like these are relatively cheap but if you can’t weigh the ingredients, use the spoon and level method (don’t scoop).
You can use shop bought lemon curd or homemade. My Easy Lemon Curd recipe takes less than 15 minutes to make.