Direction

1. Preheat the oven to 400°F. Line a 9×13 baking dish with parchment paper, carefully folding the edges so you can easily lay the crackers flat.
2. Line the baking dish with crackers. If using Ritz, the circles won't line up perfectly, so break a few into halves and do a second layer to cover the holes. It doesn't need to look pretty.
3. In a medium saucepan, heat the butter and brown sugar over medium heat, stirring frequently until fully combined and smooth. Allow it to reach 285°F using a candy thermometer and then let it stay at this heat for 3-4 minutes.
4. Remove the mixture from the heat and whisk in the vanilla. The mixture will spit a little, this is normal. Pour it over the crackers while hot. It will start to set immediately.
5. Bake the Christmas crack for 8 minutes. Remove it and turn off oven.
6. Sprinkle the top with the chocolate chips, then return to the warm oven (oven is off, but warm). Allow it to sit in the warm oven for 1-2 minutes or until the chocolate starts to glisten slightly. Using an offset spatula, smooth it out.
7. If desired, sprinkle the top with the fleur de sel, and allow to cool slightly before putting in the fridge to set. This will take several hours before toffee is easily cut.
8. Remove the parchment paper and cut into squares.