Melt the yeast with the lukewarm water then add 5 tbsp of flour. Mix the ingredients well and make a ball. Put it in a bowl covered with a cloth and let it rise for an hour in a warm place.
When it has risen well, add the rest of the flour, sugar, 3 eggs, lemon and orange zest and the melted butter. Work the dough energetically with your hands for about 10 minutes. It should be slightly on the sticky side.
Divide the dough into 3 and roll it on the table with your hands making long stripes. Make a plait out of them leaving just a small quantity of dough to decorate over the eggs.
Now join both ends of the plait making a ring and lay it on a greased baking tray. Let it rest for 2-3 hours covered with a cloth in a warm place.
Place the 4 eggs into the dough, make a cross over them with the dough stripes.
Beat an egg and brush it all over the cake and cook at 180C for 30 minutes until golden.