Take butter, milk, brown sugar in a sauce pan and mix well. bring it to a boil and boil for 2 min. It will get thick and glossy.

Now take it off the heat and add in vanilla, salt and nutella. Mix well till it is smooth.

Now pour this over the icing sugar and mix well. It will come together.

Now pour this in a pan which is lined with parchment paper.

Smoothen the top and put this in fridge to set for couple of hours.

Now remove them and cut into squares and enjoy.