Mocha Hazelnut Shortbread

Directions

1. Heat the oven to 325°F and position a rack in the middle position. Spread the hazelnut meal on a parchment-lined sheet pan (I like to use a 9x13-inch quarter sheet pan). Toast in the oven until nutty and golden brown, tossing a few times with a fork, 10 to 15 minutes. Remove from the oven to let cool and turn off the oven.
2. In a medium bowl, whisk together the cooled hazelnut meal, flour, coffee, and baking powder. In a separate medium bowl, combine the chocolate-covered espresso beans, milk chocolate, and crushed hazelnuts.
3. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, both sugars, and salt on medium speed until light and fluffy, 3 to 5 minutes. Stop the mixer and scrape down the bowl. Add the egg and mix on medium speed for 30 seconds. Stop and scrape down the bowl, then add the liqueur and beat for an additional 30 seconds, until fully combined.
4. With the mixer off, add the mix-ins. Mix on low just to incorporate. Add the flour mixture all at once and mix on low until combined with no flour streaks remaining. Stop and scrape down the bowl with a spatula, then return to low speed and mix until it comes together fully, about 10 to 15 seconds.
5. Remove the bowl from the mixer and use a spatula to fold the dough over a few times, paying extra attention to the bottom of the bowl, where undermixed bits like to hide.
6. Unmold the dough in one big mound onto a parchment-lined quarter sheet pan with a 1-inch depth (you can reuse the pan and parchment you used for the hazelnut meal toasting earlier). Using your hands, with the optional aid of a bench knife or bowl scraper, pat and shape the dough into a rectangle (aim for a little over 6 or 8 inches wide, as you will trim and cut the block into 2-inch logs later). Layer a piece of parchment on top of the dough and use a rolling pin to roll over the surface of the dough with the sides of your pin extending over the edges of your pan, as if steamrolling your dough. Your goal here is to make a block of dough with a 1-inch thickness and a flat top (if you don’t have a pan with a gusset you can just measure the edges to 1 inch and roll more gently over the surface with your rolling pin).
7. Chill the dough in the freezer until solid, at least 2 hours or up to overnight (if overnight or longer, wrap in plastic).
8. When ready to bake, heat the oven to 325°F and rearrange the racks so they are evenly spaced (avoiding the topmost and bottommost positions). Remove the dough from the freezer and let temper for 5 minutes on a cutting board. With a sharp chef’s knife, trim the edges and cut the block into 2-inch-wide logs; depending on how you have formed the dough, you may end up with 3 or 4 logs. (If you are baking all the cookies, continue; otherwise you can freeze the logs at this point, tightly wrapped in plastic or another airtight container for future baking.) Using a sharp chef's knife, slice the logs into ¼-inch-thick rectangles with one hand steadied on the top end of your knife for additional leverage. Lay the cookies onto parchment-lined sheet pans with ½ inch of space in between (that’s about 32 cookies per 18x13-inch half sheet pan. You can mash together the trimmed dough and make a few extra franken-cookies or roll the trimmings into a ball, wrap in plastic, and squirrel away in the freezer for a later date.
9. Bake for 13 to 15 minutes (if you have three oven racks you can do them all at once), rotating the pans and switching positions once after 10 minutes, until the edges are just beginning to take on color and the bottoms are evenly golden brown. Remove the trays from the oven and let cool completely on the sheet pans. Store in covered containers (I prefer tin for it’s remarkable ability to keep cookies of this variety crisp). Shortbread cookies get better as they sit and the flavors have a chance to meld: enjoy these within 2 to 3 weeks.