French pastry: Mille-Feuille

Once more I’m standing in the Sunday morning queue leading into my favorite Fontainebleau patisserie. Old ladies, mothers with baby carriages, men with dogs crowd in front of colorful window with beautiful gâteaus. ‘Deux traditionells’ (which means two baguettes classic) is the phrase with which most of them approach the counter.
As always, I’m staring at the sweets. Today I feel like Mille-Feuille. I see it everywhere, since I came to France.

Layers of puff pastry, alternating with layers of custard and glazed with white and brown fondant.
When I’ve bought it I realized that a very similar dessert has been very popular in Russia since I was a child under the name Napoleon cake (торт Наполеон). It was cooked even during the Soviet Union period (though the recipe was largely changed due to the lack of necessary products). Thus in the version which was normally cooked at my home layers of puff pastry altered with layers of cream made of butter beaten up with the equal amount of caramelized condensed milk.
I have not seen the caramelized version of condensed milk in the food stores in France. It is made by heating the canes of condensed milk during 3-4 hours. As a result the milk becomes thick and acquires the caramel taste and color. It looks this way:

And the dessert itself normally looks like this: