Dark Chocolate Buttercrunch

1 cup (16 tablespoons) unsalted butter
1/2 teaspoon salt
1 1/2 cups sugar
1 teaspoon espresso powder, optional; for enhanced flavor
3 tablespoons water
1 tablespoon light corn syrup
1 teaspoon baking soda, optional (see "tips," below)
2 cups diced pecans or slivered almonds, toasted
2 2/3 cups semisweet or bittersweet chocolate, finely chopped; or chocolate chips

INSTRUCTIONS

• In a large, deep saucepan, melt the butter. Stir in the salt, sugar, espresso powder, water, and corn syrup, and bring the mixture to a boil. Boil gently over medium heat, without stirring, until the mixture reaches hard-crack stage (300°F on an instant-read or candy thermometer). The syrup will bubble without seeming to change much for awhile, but be patient; all of a sudden it will darken, and at that point you need to take its temperature and see if it's ready. (If you don't have a thermometer, test a dollop in ice water; it should immediately harden to a brittleness sufficient that you'll be able to snap it in two, without any bending or softness). This whole process should take about 10 to 12 minutes. Pay attention; too long on the heat, and the syrup will burn.
• While the sugar mixture is gently bubbling, spread half of the nuts, in a fairly closely packed, even single layer, on a lightly greased baking sheet (a half sheet pan works well here). If you're unfamiliar with making buttercrunch, it may be easier to use a 9" x 13" pan lined with greased foil or parchment. Top the nuts in the pan with half the chocolate.
• When the syrup is ready, stir in 1 teaspoon baking soda; it'll foam up, so be careful. Pour the syrup quickly and evenly over the nuts and chocolate. Immediately top with the remaining chocolate, then the remaining nuts.
• Wait several minutes, then gently, using the back of a spatula, press down on the chocolate-nut layer to spread the chocolate around evenly.
• While the candy is still slightly warm, use a spatula to loosen it from the baking sheet. When cool, break it into uneven chunks.
• Store cooled candy tightly wrapped; it'll stay fresh for a couple of weeks at room temperature. Freeze for longer storage.

NOTES:

• I used toasted almonds (and some TJ's almond meal I happened to have) to make it Jonah-friendly
• I followed some other directions on their English Toffee post and put the chocolate chips on the bottom and sprinkled the nuts on the top.  I wouldn't do it that way again - the chips didn't quite melt and lots of the almonds just fell off the top.
• Espresso powder = instant coffee (at least it was close enough to work and that's what I had on hand)
• The baking soda step is an option, but it really does give it a better texture.  Teeny bubbles make it easier to eat.

SOURCE:  https://www.kingarthurflour.com/recipes/dark-chocolate-buttercrunch-recipe

https://blog.kingarthurflour.com/2018/12/10/tips-for-making-english-toffee/?fbclid=IwAR3w8efre0PX8BRyI4xvIVkxnK5vb0LuyyNIqNnwfvavJ9iW5T3K24AKfJ0