In a bowl, mix chocolates and butter, melt in microwave
Let stand until lukewarm then stir in sugar and vanilla
Whisk in egg one at a time
Stir in flour and sea salt
Fold in chips and toffee, plus hazelnuts
Bake on preheated 350 F for at least 25 mins (surface should be shiny and nice, while a knife inserted in the center only comes out with a little crumbs)