Prepare chocolate-covered toffee pieces by chopping them into bite-sized bits.

Preheat your oven to 375°F (190°C) and line two baking sheets with parchment paper.

In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt. Set aside.

In a large bowl, beat the softened butter, granulated sugar, and brown sugar until light and fluffy. Add in the egg and vanilla, mixing thoroughly.

Gradually fold dry ingredients into the wet mixture until just combined. Add chopped toffee.

If time allows, refrigerate the dough for up to 30 minutes.

Using a cookie scoop, portion out about 4.5 oz of dough per cookie and shape into balls.

Bake for 10 minutes, then reduce the temperature to 350°F (180°C) and bake for another 3-5 minutes until edges are golden.

Let the cookies cool on the baking sheets for about 3 minutes before transferring them to a wire rack.