7 tablespoons unsalted butter, at room temperature
1/4 cup granulated sugar
1/2 cup packed light brown sugar
1/2 cup raw almonds, chopped
1 1/4 cups flour, plus more for the work surface
1/2 teaspoon baking powder
7 ounces crushed hard toffee candy bars, such as Daim, Heath or Skor (see headnote)
1 large egg, lightly beaten
Beat the butter and sugars together in the bowl of a stand mixer or hand-held mixer on medium-high speed until light, about 2 minutes. Reduce the speed to low and add the almonds, salt, flour, baking powder and toffee bits. Finally, incorporate the egg.
Turn the dough out onto a lightly floured work surface and shape it into a uniform log about 3 inches in diameter and 10 inches long. Wrap it in plastic wrap and refrigerate for at least 30 minutes or up to 1 day.
Preheat the oven to 440 degrees. Line two baking sheets with parchment paper.
Use a sharp knife to slice the log of dough into 1/2-inch rounds. Transfer the rounds to the prepared baking sheets, spacing them at least 2 inches apart. Bake one sheet at a time for 8 to 10 minutes or until the edges are light brown, rotating the sheet front to back about halfway through baking.
If the cookies lose some of their shape during baking, you can remedy that during the few minutes immediately after they come out of the oven. Use a metal spatula to push in any wayward dough and coax the cookie back into roundness.
Let the cookies cool on the baking sheets for 5 minutes, then transfer to a rack to cool thoroughly before storing in an airtight container.