In a mixer, mix the yoghurt, eggs, orange zest, orange juice, sugar, 20 gr. baking powder and melted butter.
Cut the pastry roll in half vertically and then horizontally in smaller parts. Mix the pastry parts with your hands to get unstuck and add them to the mixture, together with 1 baking powder packet and salt. Stir.
Lay a baking pan with aluminium foil and a baking sheet on top, and pour the mixture over it. Bake at 170oC in a preheated oven for 30 min until it rises and turns slightly golden brown.
In a small saucepan, add 1 cup sugar and 1 cup water, bring to boil and add the couverture chocolate. Let it cool down a little.
Open a few holes on the surface of the orange pie with a fork.
Pour the syrup all over and place the orange pie in the fridge to cool down for at least 1.5 hr.