1. Prepare the Crust:

1. Preheat oven to 400°F (200°C). Roll out puff pastry and cut into 12 rectangles. Place on a baking sheet lined with parchment paper. Prick with a fork and bake for 15-18 minutes until golden. Cool completely.
2. In a saucepan, combine 1 cup heavy cream, milk, 1/3 cup sugar, and vanilla bean seeds and pod. Heat over medium until just simmering. Remove from heat and discard vanilla pod.
3. In a bowl, whisk egg yolks and cornstarch until smooth. Slowly pour half of the hot cream mixture into yolks, whisking constantly. Return mixture to saucepan. Cook over medium heat, stirring constantly, until thickened. Remove from heat, stir in butter and caramel sauce. Transfer to a bowl, cover with plastic wrap touching surface, and chill for 2 hours.
4. To make mirror coating: In a small bowl, sprinkle gelatin over 2 tablespoons cold water. Let bloom for 5 minutes. In a saucepan, combine 1/2 cup heavy cream, 1/2 cup sugar, corn syrup, and remaining water. Bring to a boil, then remove from heat. Add bloomed gelatin and white chocolate chips. Stir until smooth. Add vanilla extract and salt. Allow to cool to 90°F (32°C).
5. Assemble pillows: Slice each pastry rectangle horizontally to create a top and bottom. Pipe or spoon vanilla cream onto bottom halves. Place tops over cream. Refrigerate for 30 minutes.
6. Place assembled pillows on a wire rack over a baking sheet. Pour mirror coating over each pillow, ensuring even coverage. Let excess drip off. Garnish with edible gold leaf if desired. Refrigerate for 20 minutes until coating sets. Serve chilled.