Part 2/3:
In a heavy-bottomed pot, we'll combine granulated sugar, unsalted butter, salt, and water. We'll cook this mixture, stirring constantly, until it reaches the hard crack stage on a candy thermometer (290-300°F or 145-150°C). This is the key to achieving the perfect toffee texture.
Pouring and Topping
Once the toffee reaches the right temperature, we'll quickly stir in some vanilla extract and pour the hot mixture over the nuts in the prepared pan. We'll use a spatula to spread it evenly.
While the toffee is still warm, we'll sprinkle semi-sweet chocolate chips over the top and cover the pan with foil. The chocolate will melt, and we'll then spread it around for an even layer.