Step 1: Prepare the pan

Spray a 9-inch square baking dish with cooking spray.

Line it with parchment paper, leaving some overhang on the sides.

Spread 1 cup chopped pecans evenly across the bottom of the lined dish.

Step 2: Make the toffee base

In a heavy-bottomed 3-quart saucepan, add:

1 cup unsalted butter

1 cup granulated sugar

½ teaspoon kosher salt

Set over medium-low heat, stirring frequently until the sugar fully dissolves.

Step 3: Bring to boil

Increase the heat slightly and bring the mixture to a gentle boil.

Stir occasionally and evenly to avoid scorching.

Attach a candy thermometer to the side of the pot.

Continue boiling until the temperature reaches 290°F to 300°F (hard crack stage).

Step 4: Add vanilla and pour

Once the desired temperature is reached, remove from heat.

Stir in 1 teaspoon vanilla extract (carefully — the mixture may bubble).

Immediately pour the hot mixture evenly over the pecans in the baking dish.

Step 5: Add chocolate

Let the toffee sit for about 2 minutes.

Sprinkle 1 cup milk chocolate chips over the top.

Cover the dish with foil and let sit for 5 minutes, allowing the chocolate to soften.

Remove foil and use an offset spatula to gently spread the melted chocolate into an even layer.

Step 6: Cool and break

Refrigerate the toffee for at least 2 hours or until fully set and firm.

Once hardened, lift the toffee out of the pan using the parchment paper.

Place it on a solid surface or cutting board.

Break into pieces using your hands or a sharp knife.