Take the eggs out at room temperature. Separate the whites from the yolks, we're only going to be using the yolks. Lay out the puff pastry onto a floured counter and roll it out thinly (the way the original recipe calls for).
From it, cut out squares about 1 1/2″ (4 cm) per side. I made marks along the length and width and cut the squares out with a wavy knife.
Put baking paper in the oven dish and put the squares in it some distance apart. They will puff up a bit during baking. Bake in a preheated 374°F (190 °C) oven with the fan on until ready - about 15 min. Leave them to cool.
Pour the milk into a pot, along with the sugar. The sugar needs to dissolve well. Stir. Stir the yolks and starch with a little cold water in a bowl. Pour part of the warm milk into their bowl.
Pour this back into the rest of the milk and cook on moderate heat until thickened, while stirring nonstop. Once the cream is ready, take it off the stove.
Add the cinnamon stick and vanilla to flavor. Grate the rind of 1 lemon and add it as well. Stir well. Leave to cool, white stirring frequently. Once the puff pastry squares cool, cut them horizontally across the middle with a suitable knife. It's easy because during baking they become looser in the middle.
Using a spoon, distribute the cream onto the lower part (the one that was on the baking paper) and cover with the upper part. Arrange them in a platter. Finally, sprinkle with powdered sugar. What you get is a fantastic recipe. Eat with coffee and enjoy!