Thanks to Rich Buckley for this recipe, which I have adapted slightly.
2 sticks butter
1/2 cup old, cold, strong coffee
2 tablespoons corn syrup, light or golden
1 1/2 cups sugar
1/8 teaspoon sea salt
1 cup or more chocolate chips or bars. I use Ghirardelli bittersweet chocolate chips.
1/2 cup or more piñon or other nuts. I finely crush all nuts except piñons, which I leave whole. I also toast the nuts in a 300ºF oven for 10 minutes.
Line a baking sheet with silpat, heavy duty foil or parchment paper.
Melt butter in large, heavy-bottomed saucepan. Add coffee, corn syrup, sugar and salt. Stir over medium-high heat until boiling. Brush down sides of the pan with a wet pasty brush to eliminate any sugar grains. Boil until mixture reaches 285ºF. When mixture begins to darken, turn down the heat and stir constantly, as it will reach 285ºF fairly quickly, and there is a danger of scorching at this point.
Pour boiling mixture onto prepared baking sheet. Spread with silicone spatula, let cool just a bit.
Sprinkle chips or place bars over the surface of the hot toffee. Let chocolate sit for a couple of minutes until it softens, then spread over toffee with a silicone spatula. Press nuts into warm chocolate. A plastic bag over your hand makes the process of pressing nuts into the chocolate less messy.
Set tray in the refrigerator to cool for 30 minutes. Break into pieces.