Instructions

Place a rack in the upper third of the oven and preheat oven to 350 degrees F.  Grease a 8×8-inch baking pan, line with parchment paper (so that it over hangs slightly from the pan) and grease the parchment paper.  Set aside.

To make the crust, in the bowl of a stand mixer fitted with a paddle attachment cream together butter and sugar until light and fluffy, 3 to 5 minutes.  Stop the mixer and scrape down the sides of the bowl.  Add flour, cocoa powder, and salt.  Beat on low speed until dough is incorporated.  Dough may come together, but if it remains shaggy, that’s fine too. Mix in chocolate chips if desired.

Dump the crust into the prepared pan and use your fingertips to press the dough into the bottom of the pan.  Bake for 15 to 18 minutes until just browned around the edges.

You can make the filling while the crust is baking. In a medium bowl, add sugar and orange zest. Massage the zest into the sugar unil well incorporated and all sugar is orange-y. Add eggs to the sugar mixture and whisk until well combined and slightly thick. Add the flour, orange juice, and whisk until blended.

Pour the filling over the still warm baked crust.  Return to the oven and bake for 18 to 20 minutes, or until lightly browned on top and no longer jiggling in the center.

Allow to cool completely in the pan. Once cooled, dust with powdered sugar. Run a knife around the edges of the pan.  Slice bars into nine squares. Use the over hanging parchment paper to lift the squares out.  To store the bars, place them in an airtight container separated by wax paper layers.