Step 1

Line a 9x13” pan with foil and spray with cooking spray. You can also use parchment, if you prefer.

Step 2

Melt butter in a 2-quart heavy saucepan over low heat. Use a pastry brush to brush some of the butter up the sides of the pan to prevent crystallization. Stir in sugar, water, and corn syrup. Bring to a boil over medium-high heat, stirring until sugar is dissolved. Try not to splash the side of the pan too much or the sugar will stick and crystalize; stir gently.

Step 3

Once sugar is dissolved, place a candy thermometer in your pan and cook over medium heat, stirring frequently, until the candy thermometer reaches 290°F (soft-crack stage). This will take from 10-14 minutes, depending on your stove. Watch the heat and adjust it as necessary to keep the boiling uniform throughout cooking. Don’t walk away from the stove; watch it especially carefully during the last 5 minutes or so as it can reach temperature fast. Remove thermometer once it gets to 290°F. Turn off heat, stir in vanilla and salt quickly. Pour into prepared pan.

Step 4

Sprinkle with chocolate chips. Let them sit for about 2 minutes then use a knife or offset spatula to spread the chocolate evenly. Sprinkle with nuts.

Step 5

Let sit at room temperature about 3 hours or until set. Remove toffee from pan using foil, remove the foil and then break into pieces. Store in an airtight container for up to two weeks.