To begin, preheat oven to 180°C and line cupcake tin with 12 paper cases.
Using the bowl of a free-standing mixer, add the butter, sugar, eggs, lemon juice and zest, before sifting in the flour and baking soda. Beat for about 60 seconds until smooth.
Lower the speed and slowly add the milk before turning mixer back up for about another 30 seconds.
Fill paper cases about two-thirds full and bake for 18-20 minutes or until cake springs back when touched. Allow to cool completely before filling the centre with lemon curd.
For the frosting, add the egg whites, sugar, golden syrup and cream of tartar to a heat-safe bowl and place over top of a pot of simmering water.
Using a hand-held beater, beat the frosting ingredients for 5-8 minutes over top of the simmering water. Frosting will turn pale, increase in volume, thicken and texture should become smooth when sugar is dissolved.
Either pipe or spoon meringue frosting over top of cupcakes before meringue topping sets and becomes too firm. For that added touch, you can also use a blowtorch to char your meringue frosting. Enjoy.