Preparation

Pastry shells:
• Combine the flour and sugar in a small bowl. Set aside.
• In a saucepan, bring 1 cup water, butter and salt to a simmer until the butter has melted.
• Remove from heat and add in the flour and sugar mixture, whisking constantly until it comes together as a batter.
• Add the eggs 1 at a time, whisking constantly until mixed. Store in the fridge until chilled.
• Preheat oven to 375 degrees. Line a baking sheet with parchment paper.
• Transfer the chilled dough to a pastry bag and attach a star tip. Pipe the batter onto the parchment paper in 5- to 6-inch strips, leaving a curled tip at the end of each éclair. Wet your finger and gently press down those tips so they don't stick out.
• Place the baking sheet in the oven and immediately lower the temperature to 350 degrees. Bake for 40 minutes, rotating the pan halfway through.
• Lower the temperature to 325 degrees and bake another 20 minutes, until golden brown.
• Lower the temperature to 300 degrees and bake 10 more minutes, until the éclairs feel light (To check, break one open and check the inside – it should be completely cooked). Let cool completely before filling or freezing.

Apple cider filling:
• In a saucepan, bring the milk to a simmer.
• In a large bowl, whisk the egg yolks and sugar until slightly pale. Add the cornstarch and whisk 1/3 of the hot milk into the mixture, until combined. Add the mixture to the saucepan.
• Bring to a boil over medium heat while whisking, making sure not to cook the yolks, until slightly thickened. Remove from heat and let cool 10 minutes
• Incorporate half the butter. Pour the mixture into a baking dish, cover with plastic wrap, and let cool.
• Once the filling reaches room temperature, transfer it to the bowl of a stand mixer and beat until smooth. Beat in the boiled apple cider and the remaining butter.
• Cover with plastic wrap and refrigerate for at least 1 hour.

Caramel glaze:
• In a medium bowl, stir 1/3 cup water, salted caramel sauce, boiled apple cider, powdered sugar and cinnamon until combined. Add more water if mixture is too thick; add more powdered sugar if it’s thin. It should spread easily and harden quickly.

Assembling éclairs:
• Cut the éclair shells in half lengthwise.
• Fill a piping bag with the apple filling and attach a round tip. Pipe a layer of filling onto the bottom halves of the pastry shells. Sandwich the filling with the top halves.
• Spoon the glaze over the tops of the éclairs and let harden.
• Eat immediately or store chilled in the fridge for 1 day. The shells, filling and glazes can be kept chilled or frozen 1 to 2 weeks.

Boiled Apple Cider
Make boiled apple cider (also called apple molasses) by placing about 4 cups apple cider in a large saucepan and a cinnamon stick, star anise or both. Bring to a boil, then reduce heat to medium-low and let simmer, stirring occasionally, for 4 to 5 hours, until it is reduced to a thick syrup. Store covered in the refrigerator. Boiled apple cider also can be purchased online.