Chocolate Éclairs

Preheat the oven to 425°F, with racks in the upper and lower thirds. Line two large baking sheets with parchment paper or nonstick baking mats, such as Silpats. With a ruler and a pencil, mark lines about 3 1/2 inches long on the parchment, spacing them about 1 1/2 inches apart (you should be able to fit 16 lines on each sheet). Turn parchment over, marked sides down. Fill a pastry bag fitted with a 1/2-inch plain tip (such as an Ateco #806) with Pâte à Choux; pipe along the lines on the prepared baking sheets. Gently smooth tops with a moistened fingertip to ensure even rising.

Bake for 10 minutes; reduce oven temperature to 350°F. Continue to bake, rotating sheets halfway through, until pastries are golden brown, 25 to 30 minutes more. Transfer pastries and parchment to a wire rack to cool completely.

Place chocolate in a medium heatproof bowl. Heat 3/4 cup cream and corn syrup in a small saucepan over medium heat until bubbles begin to appear around the edges, about 5 minutes; pour mixture over chocolate. Let stand 5 minutes, then stir until smooth. Let cool, stirring occasionally, about 5 minutes.