Oven temperature: 180 °C
1 Line two 22 x 34cm* rectangular roasting pans with baking paper and spray well with non-stick cooking spray. Preheat the oven.
2 Beat the eggs, salt and sugar together with an electric beater or mixer until light and fluffy (it usually takes about 10 minutes to get good volume). Sift the cake flour and baking powder together in a separate bowl. Also mix the yoghurt, condensed milk and bicarb in a third bowl until just smooth.