Orange chocolate tarts

Make the chocolate shortbread: In a bowl, stir together the flour, salt and cocoa powder and set aside. Cut the butter into 1/2-inch pieces, then combine it with the sugar in the bowl of a stand mixer fitted with the paddle attachment. Beat on low speed until the butter and sugar begin to incorporate, about 15 seconds. Add the dry ingredients and continue to mix until the dough comes together, about 3 minutes. It will look dry just before it comes together.

Divide the dough equally between two 12-cup muffin pans. Press the dough to cover the bottom of each cup by 1/4-1/2 inch. Refrigerate until firm, at least one hour.

Preheat the oven to 300 degrees. Bake the shortbread until firm, about 35 minutes. (Both muffin pans should fit on the same oven rack.) At the midway point, rotate the muffin pans 180 degrees to ensure even baking. Let cool in the muffin pans 10 minutes. Gently remove the shortbread and cool it to room temperature on wire racks. Once cool, liberally brush Grand Marnier onto the cookies. Let the liqueur seep into the shortbread before topping the tarts with the mascarpone mixture.

As the shortbread cools, make the topping: In a large bowl, stir together mascarpone, confectioners sugar and orange zest. Spoon the mixture into a pastry bag outfitted with a large tip. Pipe the mixture onto the cookies in a thick swirl, making sure to cover the top of the shortbread.

Serve immediately, or cover and refrigerate before serving. The tarts should be assembled and served on the same day.