Saltine Toffee

Steps

1. Heat the oven to 400°F. Line a 10x15-inch rimmed baking sheet with foil and butter the foil well.
2. Lay the saltines in a single snug layer, breaking some to fill the gaps. You may have a few left over.
3. Melt the butter with the brown sugar in a medium saucepan over medium heat, stirring, and bring it to a full, rolling boil.
4. Set a timer for 3 minutes and let it bubble hard with no stirring. It will turn thick, foamy and a shade darker, and a candy thermometer should read 270°F to 290°F, the soft-crack stage.
5. Pour the toffee over the crackers right away and spread it to cover them. Bake for 5 minutes, until it bubbles all over.
6. Sprinkle the chips evenly over the toffee as soon as it comes out of the oven. When they turn soft, after 3 to 5 minutes, smooth them into an even layer with an offset spatula.
7. Sprinkle on the pecans and flaky salt, if using, and press them in lightly.
8. Cool on the counter for 15 minutes, then refrigerate until firm, about 1 hour. Peel off the foil and break into pieces.

Good to know

• It stays crisp for about 2 weeks in a sealed tin in the fridge, and for about 3 months in the freezer.
• If the toffee layer is chewy instead of crisp, it did not cook long enough. Next time, check it with a thermometer and pour once it reaches 270°F.
• Swap in milk or white chocolate chips, or top with crushed candy canes or holiday sprinkles instead of nuts.
• For gifts, layer the pieces in tins between sheets of wax paper and keep them cool so the chocolate stays firm.