Making Classic Christmas Toffee is a joy once you follow these simple steps:

1. Prepare the Baking Sheet: Line a 9×13 inch baking sheet with parchment paper, ensuring it hangs over the edges for easy removal later.
2. Melt Butter: In a heavy-bottom saucepan, melt the butter over medium heat.
3. Add Sugars and Salt: Stir in the granulated sugar, brown sugar, and salt until fully combined.
4. Boil Mixture: Bring the mixture to a gentle boil, stirring constantly. Use a candy thermometer to monitor the temperature.
5. Reaching Temperature: Cook until the mixture reaches the hard crack stage, which is about 300°F (150°C). This usually takes around 15-20 minutes.
6. Add Vanilla: Once the desired temperature is reached, remove the saucepan from heat. Stir in the vanilla extract quickly to combine.
7. Pour into Baking Sheet: Immediately pour the toffee mixture onto the prepared baking sheet, spreading it evenly.
8. Cool Slightly: Let the toffee cool for about 5 minutes, just until it’s not bubbling.
9. Add Chocolate: Sprinkle the chocolate chips evenly over the hot toffee. As they melt, spread them out smoothly with a spatula.
10. Add Nuts and Sea Salt: If using, sprinkle the chopped nuts over the chocolate layer. Finally, add a sprinkle of sea salt on top for an extra flavor boost.
11. Cool Completely: Allow the toffee to cool completely at room temperature or refrigerate it for a faster process.
12. Break into Pieces: Once set, use your hands to break the toffee into pieces of your desired size.

Following these steps will yield a gorgeous batch of Classic Christmas Toffee that everyone will adore.