Preheat oven to 350 degrees. Spray a 9" round cake pan with nonstick baking spray.
Add the sugar and orange zest to a bowl and mix for a couple of minutes to release the oils from the zest and infuse the orange flavor into the sugar.
Add your eggs, oil, orange juice, yogurt, and vanilla extract and mix for a couple of minutes until the sugar is partially dissolved and the mixture is lighter in color.
Add your dry ingredients and mix until just combined, careful not to over mix.
Pour your batter into the prepared cake pan. Bake for 30-35 minutes or until a toothpick comes out clean.
Allow to cool completely.
Once cool remove the cake from the pan and place on a serving plate or cake stand.
Pour the chocolate hazelnut spread over the top and smooth out with an offset spatula.