Prepare an 11”x17” rimmed baking sheet by greasing the sides and lining the bottom with parchment paper
Combine 16 ounces of cubed salted butter with 2 cups of granulated sugar, 2 tablespoons of light corn syrup, 2 tablespoons of water and 2 teaspoons of vanilla extract in a sauce pan and place over medium heat
Bring to a boil and then adjust the heat to maintain a gentle boil
Boil while occasionally stirring until the mixture becomes golden brown and has thickened
Pour the toffee over the prepared baking sheet
Sprinkle the chocolate over the entire surface of the hot toffee and let it sit for a minute or so it has a chance to soften
Spread the chocolate evenly and add your chopped nuts
Cover the baking sheet with foil or a clean kitchen towel and let the toffee set for about an hour (either at room temperature or in the refrigerator)
Use the parchment paper to lift the toffee out of the baking sheet and place it onto a hard surface
Drop the toffee onto a hard surface or pierce it with a sharp knife to form cracks throughout the toffee
Store layered with parchment paper in an airtight container either in a coolr, dry place or in the refrigerator