Cream the egg and oil until it becomes creamy and pale, add the sugar and mix it until the sugar starts to dissolve. Add the rest of the ingredients, making sure they're thoroughly mixed in without over-mixing them. Use around two tablespoons of the mixture for each cookie, making sure to keep a few centimetres between them as they do spread quite a lot. The dough is really sticky so don't try to roll balls with them, simply place a tablespoon of cookie dough in a lined tray, moisten your fingers with cold water and pat them down a bit to make space for the Nutella (wether you're using real one, the previous recipe or your own), use around 1/2 a teaspoon of Nutella for each cookie and then place another tablespoon of the cookie dough on top. With your fingers moistened make sure both halves of the cookies are well combined and completely covering the filling. You should end up with 12 large cookies.

Bake them in a preheated oven at 175ºC for 10 to 13 minutes. They won't look done, but they will continue to bake as they cool down. Let them cool a bit in the tray before using a spatula to move them to a cooling rack, otherwise they'll break. And there you go, the easiest cookies to bake and eat you'll ever find.