1. Preheat oven to 180C (160C fan-forced),and place paper cases into a large cupcake tray.
2. In the bowl of an electric mixer,beat the butter and sugar until pale and smooth,about 3 minutes. Scrape down the sides once or twice,for a smoother mixture.
3. Add the eggs one at a time,beating between each addition.
4. Working quickly and lightly,fold in half the sifted flour with a spatula,followed by half the yoghurt. Fold in the remaining flour,followed by remaining yoghurt,lemon juice and zest.
5. Using two spoons – one to pick up the mixture,one to scrape off – fill the paper cases to just two-thirds-full. Bake in the centre of the oven for 20 minutes or until the top is springy to the touch and an inserted bamboo skewer comes out clean. Allow to cool completely on a wire rack.
6. To make the icing,mix the yoghurt and lemon juice into the sifted icing sugar and beat until thick and smooth,adding extra lemon juice by the drop until you have a soft consistency. Drip a teaspoonful on each cake,tilting to help it slowly spread. Top with a lemon jube and allow to set before serving.
Tip:You can use an ice-cream scoop to evenly divide the cupcake batter between paper cases.