Preheat the oven to 375°F. Turn a sheet pan over, cover it with parchment paper, and unroll the sheet of puff pastry. Cut off any protruding edges and sprinkle sugar on the dough.
Put a sheet of parchment paper on top of the puff pastry and place another sheet pan over the dish. Slide the pans into the oven and bake for 25 minutes.
Remove the puff pastry from the oven and let it cool down. Cut the sheet into 4 equal sections and place on a cooling rack.
In the meantime, prepare the vanilla pudding by heating the milk and vanilla bean contents together in a pot. Bring to a boil, reduce the heat, and let sit for about 10 minutes. Mix the egg yolks, sugar, and corn starch in a separate bowl and fold the contents into the vanilla milk. Stir the pot continuously over medium heat and finally add the soft butter. Mix well, remove from the stove, cover the pot with plastic wrap, and let the pudding cool down.
Once the pudding has completely cooled, spread it over 3 of the puff pastry rectangles.
To prepare the glaze, stir the powdered sugar and lemon juice together until smooth, spread the mixture over the last puff pastry rectangle, and smooth it out with a knife.
Use a spoon to drizzle the melted chocolate over the glaze and pull a knife through it, as shown in the video.
Stack the 4 puff pastry rectangles on top of one another, with the glazed rectangle on top.
