How to make
Mix the yogurt with the soda and add the mixture into the bowl with the well beaten eggs and sugar. Homogenize the mixture and while stirring continuously, add the salt, flour, oil and the juice and peel of one orange.
Pour the resulting sponge cake batter into a mold with a diameter of 9″ (23 cm), pre-greased and floured. Put the plain sponge cake with yogurt to bake in an oven heated to 360°F (180°C) with a fan for about 50 minutes.
Pierce the surface of the baked sponge cake with a skewer and pour the squeezed juice from the second orange over it. Sprinkle with powdered sugar and serve it chilled.
