Melt the dark chocolate with the butter, be careful not to burn it. Add the Nocciolata at room temperature and mix with a whisk. When the mixture is blended, add the eggs, cocoa powder, sugar, yeast, flour, and starch. Mix, then add the salt and the halved walnuts. Grease the sides of the mold and line the bottom with parchment paper. Pour batter into the pan and bake at 325°F for about 40 minutes. Check with a toothpick that the center is moist but does not remain on the toothpick. Leave to cool in the pan.
Prepare the glaze by melting the chocolate with the butter, then adding the whipping cream and mixing until a smooth cream is obtained. Glaze the brownies and put them in the fridge. When the glaze has hardened, unmold the brownies and cut them into squares.
Decorate with a caramel sauce and enjoy!