A friend at work started a toffee making business called Bellstone Toffee. It is fabulous, and I had to give it a try for myself. This isn't her recipe, but one inspired by the Saveur article I read (see Peppermint Patties post).
Makes About 2 1⁄2 Pounds
2 tsp. plus 2 cups butter
2 cups sugar
2 tbsp. light corn syrup
2 tsp. kosher salt
2 cups chopped toasted pecans
2 c. semisweet chocolate chips*
1. Grease the bottom and sides of a 10"×15" jelly roll pan with 2 tsp. butter and set aside. Put remaining butter, sugar, corn syrup, salt, and 1⁄2 cup water into a medium pot and bring to a boil over medium-high heat while stirring constantly. Attach a candy thermometer to inside edge of pot and cook, continuing to stir constantly, until sugar mixture is deep golden brown and registers 310°, about 20 minutes. This feels like it takes forever, but COOK ON!
2. Pour the hot toffee onto the prepared pan and, using oven mitts, tilt and turn the pan to fill it evenly. Let the toffee cool for 5 minutes, then sprinkle 2 cups semisweet chocolate chips over the top. Let sit for 1 minute, then use a rubber spatula to gently spread the melted chocolate evenly over the top. Sprinkle the pecans over the chocolate and gently press them down.
3. Refrigerate toffee until it hardens, about 1 hour, then break into bite-size pieces. Serve toffee immediately or store in an airtight container in the refrigerator for up to 2 weeks. Note - don't line the container with paper towel like I did. It will stick!
* next year, I will try to top it with tempered chocolate. It got a little streaky if you make some without nuts, like I did, for my nut allergy family members.