Christmas Log - a Portuguese family recipe

I am from a large Portuguese family who immigrated to Canada.  I only have one younger sister, but my 9 uncles and 9 aunts ensured our house was full of cousins at Christmas time (27 of us, before marriage).

Christmas, as with any family reunion, was all about eating - it wasn't something ever mentioned or spoken about, directly, but each family had a culinary responsibility for the Christmas eve dinner - and everyone clearly appreciated the traditional recipes each family member specialized in... and when everything got layed out on the table, it would be a culinary feast that lasted at least 6 hours. 

One of the Christmas desserts that always made its appearance on the table was my aunt's Christmas log.  A very light and fluffy white log filled with chocolate, sprinkles, and sugar.  In theory, this is a very simple recipe - but baking is a game of chemistry where every single element must be exact.  This is the key to succeeding this delicious family recipe of mine. 

Prep time:  10 mins
Baking time: 10-12 mins
Preheat oven to 180ºC

Ingredients:
6 eggs (separated)
10 tblsps of granulated sugar
6 tbls of plain white flour
1 tsp of Baking powder
Rind of 1 orange (or any other citrus fruit)

1/2 egg shell of water

First, beat the egg whites until stiff and set aside.

Then, mix the egg yolks and sugar until the mixture is fluffy and has whitened considerably.

Add the flour baking powder Orange rind and water to the egg yolk mixture

Fold in the egg whites - the batter should be fluffy and inflated

Pour into a baking sheet that has been previously greased with butter and floured. 

Use a spatula to carefully spread out the batter over the sheet.  Insert in preheated oven for 10-12 minutes or until a toothpick inserted throughout the cake comes out clean.

Here comes the tricky part...
Let the cake cool in the baking sheet for no more than 5 minutes.  Then, cover the cake with granulated sugar.  Put a clean kitchen towel over the cake and baking sheet and turn over so that the cake rests on the kitchen towel (the granulated sugar prevents it from sticking to the kitchen towel).

Quickly, spread a thin layer of chocolate spread (homemade or Nutella) or any other spread you prefer (jam, dulce de leche, etc).  Then, take one end of the cake and using the kitchen towel, roll it up, as you would a sushi roll. The kitchen towel helps to prevent burning your fingers, but it also helps to evenly apply pressure as you roll up the cake (do not roll up the kitchen towel, LOL)

Lay it out on a plate and decorate with chocolate, icing sugar, christmas figurines etc.

Let me know if these instructions make sense or if you need any additional information on any steps.