Puff Pastry Cream Horns

§ PROCEDURE

1. Make the dough: combine 625 g flour, 400 g water, 50 g room-temperature butter, and a pinch of salt. Mix until a soft, smooth dough forms — about 20 minutes by hand or 10 minutes in a stand mixer. Cover and rest for 10 minutes.
2. On a lightly floured surface, roll the dough into a 12×12 inch square. Place 500 g of room-temperature butter in the center. Fold each corner of the dough over the butter to encase it completely, pinching the seams to seal.
3. Roll the dough-butter package into a 10×24 inch rectangle, dusting with flour as needed. Book fold: fold both short ends in to meet at the center, then fold the whole piece in half along that center line — like closing a book. This creates 4 layers. That is one book fold. Rotate the dough 90 degrees.
4. Repeat the rolling and book folding process. Do at least 3 book folds, with 5 being optimal. If the kitchen is warm, refrigerate the dough for 10 minutes between folds to keep the butter from softening into the dough.
5. Once lamination is complete, extend the puff pastry and cut it in half. Working with one half at a time, roll and extend the dough to an even thickness, then cut into 8 long strips.
6. Starting from the pointed tip of a metal cream horn mould, wind one strip of dough around the cone, overlapping each wrap slightly as you work toward the wide end. Press the final end against the last layer to seal. Repeat with all 16 strips. Place the filled moulds on a parchment-lined baking sheet.
7. Beat the egg and brush the egg wash over all the pastries. Bake at 375°F (190°C) for about 30 minutes, until deep golden brown. Let the horns cool completely on a rack before removing the moulds — the metal stays hot for several minutes after baking.
8. Make the pastry cream: heat 500 ml of milk in a saucepan over medium heat. Add 150 g sugar and stir until dissolved. In a small bowl, mix 80 g corn starch with 120 ml water until smooth. When the milk is just about to boil, pour in the corn starch slurry and add 1 tsp vanilla extract and a few drops of food coloring if using. Stir constantly over medium heat until the cream thickens and is no longer runny, a few minutes. Remove from heat and let cool completely.
9. Transfer the cooled pastry cream to a piping bag fitted with a large round tip. Pipe generously into each cream horn from the wide end. Serve immediately or refrigerate until ready.

§ OBSERVED RESULT

The laminated dough separates into visible distinct layers during baking, the butter creating steam pockets that push each sheet apart. The exterior is shattering-crisp, the interior slightly soft. The pastry cream is dense and cold against the warm crunch of the shell. Earth specimens consume these in two or three bites. I have not found a way to make them last longer.