Preheat oven to 350 degrees.
In a stand mixer combine Nutella, eggs and flour. Mix well and transfer to a foil lined 7X11 brownie pan.
Bake for 25-30 minutes.
Over a double boiler bring water to a boil and turn off the flame. Add the chocolate or candy melts and stir, allowing the steam alone to melt the chocolate in the bowl. An actual flame will be too hot.
Pour over cooled brownies and top with the chopped candy. Cut the brownies when the chocolate has cooled half way, about 15 minutes. If you wait too long the chocolate will break when you try to cut them.
Allow the cut brownies to cool completely before serving.