1: Whisk egg yolks, sugar, and cornstarch until smooth.
2: Slowly pour your warm milk; transfer to the stove over medium-low heat and start stirring until it thickens. Optionally, run it through a sieve for extra smoothness, stir in vanilla bean paste and transfer into a pastry bag and refrigerate until cool.
3: Roll your puff pastry dough over a floured surface and cut it into 12 strips.
4: Roll each strip onto a metal horn, ensuring it overlaps half way of its width.
5: Brush egg wash and sprinkle coarse sugar and/or crushed pistachios.
6: Bake at 400°F for about 20-22 minutes.
7: Transfer the horns onto a cooling rack and fill them with the cooled custard.
8: Sprinkle some powdered sugar, serve with berries, mint leaves, and the remaining custard for extra dipping and enjoy!
