1) Start your oven at 180C/ 356F.
2) Put your egg yolks into a large bowl. Then, mix in one by one the sugar, then the yoghurt and baking powder, your sifted flour and finish by the vegetable oil.
3) Separately whisk your egg whites into a firm foam.
4) Next, blend about two table spoons of the stiff egg whites into the batter. Do this by stirring well your whites with a whisk, lifting the batter from the bottom of the bowl onto the top of the mixture. Finally add the rest of your whites and the hazelnuts to the batter, in the same way.
5) Bake for 35-40 minutes in a round non-stick mould. Test the cooking by pricking the middle of your cake with an office knife. It must come out almost dry.
Serve with a caramel flavoured custard.
credits photo : Patrick.Asfaux© A.F.Touch