Separate eggs: one bowl for egg whites and the other bowl for egg yolks.
Mix egg whites on high speed for 5 minutes in large mixing bowl.
In a different mixing bowl, combine yolks and sugars until sugar is well dissolved.
Add oil and cold water.
In a separate bowl, combine baking powder with flour.
Continue mixing at the lowest speed. Add flour mixture slowly spoon by spoon.
Similarly, add the egg white mixture spoon by spoon and mix slowly until all combined.
Place parchment paper inside a 9x13 pan and then grease well with oil.
Pour the batter and level in the pan.
Bake for 12-15 minutes at 370F.
Remove from the oven and flip the pan on top of a clean tea towel so the parchment paper side is up. Put the pan aside.
Peel off the paper.
With the towel, roll the sponge cake to help loosen and prevent it from cracking afterwards.
Leave it too cool completely in a rolled position.
When cool, unroll and then spread nutella on top.
Then roll again without a tea towel.
Place in the fridge for one hour.
Remove and sprinkle with sifted powdered sugar to serve.