Chocolate Orange Tart

To prepare the tart dough, in the bowl of an electric mixer fitted with the paddle attachment, cream the butter and sugar until combined, about 1 minute. Add the egg yolk and cream and beat until smooth. Sift in the flour and cocoa powder and beat on low speed until just combined. Scrape the dough onto a sheet of plastic wrap and form it into a disk. Wrap and chill until firm, about 1 hour, or up to 3 days.

Preheat the oven to 325 degrees F. On a lightly floured surface, roll the dough to an 18×12-inch rectangle, 3/16 inch thick. Cut out a circle 1 – 1/2 inches larger than your tart pan. Place the dough in the tart and chill the tart shells for 20 minutes.

Line the tart shells with foil and fill with dried beans, rice, or pie weights. Bake for 15 minutes. Remove the foil and weights and bake for 5 to 10 minutes longer, or until the pastry looks dry and set. Transfer to a wire rack to cool. (The tart shells can be made 8 hours ahead).

To make the ganache filling, in a saucepan, bring the cream and liqueur to a boil. Place the chocolate in a bowl. Pour the hot cream mixture over the chocolate and let sit for 2 minutes, then whisk until smooth. Pour into the prepared tart shell. Let stand until set, about 2 hours, or chill for 1 hour.