Begin by making your chocolate-covered toffee if not pre-prepared. Chop the cooled toffee into small pieces, aiming for roughly 1-inch chunks for a satisfying crunch. Set them aside in a bowl, ready to be incorporated into your cookie dough.

Preheat your oven to 375°F (190°C), ensuring it reaches the right temperature for even baking. While the oven is heating, line two baking sheets with parchment paper to prevent sticking and facilitate easy cleanup later on.

In a large mixing bowl, whisk together the all-purpose flour, unsweetened black cocoa powder, baking powder, baking soda, and salt. This step is crucial as it evenly distributes the leavening agents and adds air, contributing to the cookie's fluffy texture.

In a separate bowl, beat the softened unsalted butter with granulated sugar and brown sugar until the mixture becomes light and fluffy, about 2-3 minutes. Next, add the room-temperature egg and pure vanilla extract, mixing until smooth and well combined.

Gradually fold the dry ingredients into the wet mixture using a rubber spatula, being careful not to overmix. As the dough comes together, gently fold in the chocolate-covered toffee pieces, making sure they’re evenly distributed throughout the dough for that heavenly taste in every bite.

For enhanced flavor and texture, consider chilling the cookie dough in the refrigerator for about 30 minutes. This step is optional but highly recommended, as it allows the flavors to meld and the dough to firm up slightly for better shaping.

Using a large cookie scoop, scoop generous portions (about 4.5 oz) of dough and roll them into balls. Place them on the lined baking sheets, leaving ample space between each cookie to allow for spreading during baking.

Bake the Levain Bakery Coffee Toffee Cookies in your preheated oven at 375°F for 10 minutes. After that, reduce the temperature to 350°F and continue baking for an additional 3-5 minutes, until the edges are set and the centers remain slightly soft.

Once baked, allow the cookies to cool on the baking sheets for 3 minutes. This cooling time helps them set up perfectly. After that, gently transfer the cookies to a wire rack to cool completely, allowing for the ideal chewy texture as they finish baking.