Preheat your oven to 160C Fan / 180C and prepare a large baking tin with non-stick baking paper.

Place your Nutella in a bowl (loosen it by briefly heating in the microwave if you need to)

Add in your egg and mix it in.

Add your flour in and give it a thorough mix so that it forms a dough and no flour is showing.

Weigh out about 50g of the dough and roll it in to a ball. Then optionally flatten it in your hands and place a cube of chocolate into the centre of the flattened dough. Bring the dough together around the chocolate chunk and roll it up into a ball again.

Place your balls onto a tray, I only place 6 per large tray as they will spread a little.

Gently press each ball down, but not too much, just a little. Optionally stick a few chocolate chips in the top of each one.

Place in the oven for around 8-10 minutes, until slightly spread but with still a little raised middle (the less you cook them, the more raised the middle will be, resulting in a gooey centre - IF you have added the chocolate chunk of course)

Remove from the oven and allow to cool. They will be very soft so don't touch them until they have cooled down and firmed up a bit!

Once more firm you can pick them up and... eat them!! If you added the chocolate chunk to the centre then break it down the centre for a gooey middle!