Chocolate Truffle Cookies with Whipped Nutella Ganache

Make the Chocolate Truffle Cookies:

In a medium bowl, sift together the flour, cocoa powder, baking powder, and salt. Whisk to combine.

In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and sugar on medium-high speed until light and fluffy, 1 to 2 minutes. Add the egg and vanilla and mix to combine. Stop the mixer and scrape down the sides of the bowl as needed. Gradually add the flour mixture and mix on low speed until just combined.

Transfer the dough to your work surface and divide it in half. Wrap one half in plastic and set aside. Use a rolling pin to roll the other half of the dough between two large pieces of parchment paper until it is about ¼-inch thick. Repeat with the second half of the dough. Stack the parchment-lined dough slabs one on top of the other on a baking sheet and refrigerate for 2 hours, until firm.

Once the dough has chilled, preheat the oven to 350 degrees. Line two baking sheets with parchment.

Use a 2-inch round cookie cutter (or shape of your choice) to cut rounds of dough and transfer them to the prepared baking sheets. Place them 1 inch apart; the cookies will not spread while baking. 

Bake for 10 minutes. Remove from the oven and, using a spatula, carefully transfer the cookies to a wire cooling rack to cool completely. (If you use smaller cookie cutters, decrease the baking time and check for doneness at 8 minutes. The cookies will not jiggle but they will still be slightly soft in the middle. They will firm up as they cool.)

Make the Chocolate Coating:

Place the chocolate chips and coconut oil in a microwave-safe bowl. Melt in the microwave in 30-second increments, stirring in between. Continue until the chocolate is smooth and shiny.

Line a baking sheet with parchment or wax paper. Dunk the top of each cookie in the melted chocolate and then transfer to the lined baking sheet.

Assemble the cookies: Once the chocolate coating has set, fill a piping bag fitted with a large star tip with the Whipped Nutella Ganache. Pipe swirls of ganache on the flat side (opposite the chocolate-covered side) of half the cookies. Top the frosted cookies with the remaining cookies, chocolate-side up. Place in the refrigerator for 30 to 60 minutes to set. (Alternatively, you can use the back of a spoon to spread the cookies with ganache. When topping them with a second cookie, smooth the edges of ganache with a knife or clean fingers.)

Store the cookies tightly covered in the refrigerator for up to 3 days. Serve cold or let sit out at room temperature for 15 minutes before serving.

Make the Whipped Nutella Ganache: 

Place the chopped chocolate in a heatproof bowl. In a small saucepan over medium-low heat, heat the heavy cream until just simmering. Do not let it boil.

Pour the hot cream over the chopped chocolate and let sit for 5 minutes. Add the Nutella and whisk to combine.

Allow to cool to room temperature, stirring occasionally. At this point, you may place the ganache in the refrigerator to speed this along.

Once cooled, transfer the ganache to the bowl of a stand mixer fitted with the paddle attachment and whip on high speed until light and fluffy, 2 to 3 minutes. It will lighten in color and the whipped ganache should hold its form.

Use immediately or store tightly covered in the refrigerator for up to twp weeks.