Prepare your workspace:

• Line a baking sheet or 9×13-inch pan with parchment paper or a silicone mat. Set aside.

2. Toast the pecans (optional):

• Preheat your oven to 350°F (175°C). Spread the chopped pecans in a single layer on a baking sheet and toast for 5–7 minutes until fragrant. Let cool.

3. Make the toffee base:

• In a heavy-bottomed saucepan, melt the butter over medium heat. Stir in the sugar and salt, and cook, stirring constantly, until the mixture reaches 300°F (150°C) on a candy thermometer (hard crack stage).
• Remove from heat and stir in the vanilla extract and half of the chopped pecans.

4. Pour and spread:

• Quickly pour the hot toffee mixture onto the prepared baking sheet and spread it out evenly with a spatula.

5. Add the chocolate layer:

• Sprinkle the chocolate chips over the hot toffee. Let sit for 1–2 minutes until the chocolate begins to melt. Spread the melted chocolate evenly over the toffee with a spatula or the back of a spoon.

6. Garnish with pecans:

• Sprinkle the remaining pecans over the chocolate layer. For an extra touch, add a light sprinkle of sea salt.

7. Cool and break into pieces:

• Allow the toffee to cool completely at room temperature, or place it in the refrigerator for faster setting. Once set, break it into pieces and store in an airtight container.