Crush the cookies, I put the cookies into pieces to blender, and average speed make them almost dust.
Then add the tablespoon of cinnamon and lemon zest and mix well. Knead the butter to form a soft dough.
With the dough ready, cover bottom of pie pan. I recommend those aluminum pie molds, are inexpensive and provide a perfect fit, plus it helps a lot when baking.
Ok, now take the mold to the refrigerator until you finish the preparation.
Preheat oven to 180 ° C (350 ° F or so ...)
Heat 1/2 cup of water with lemon zest, and besides, the other 1/2 cup cold water, dissolve a tablespoon of cornstarch.
Boiling water and zest, add the cornstarch dissolved, stirring constantly until it becomes thick, like an ATOLE.
... if it is too watery, add half a teaspoon more of cornstarch ...
When thick liquid, add the condensed milk and lemon juice. place over medium heat until boiling, without stirring. When boiling, remove from heat and add the slightly beaten egg yolks and mix well. Return to low heat for another 2 minutes stirring constantly.
Remove from heat and remove the pan from the refrigerator. Pour mixture over crust and bake.
Put oven rack slightly above the middle, to avoid burning the crust, and let the heat dry a bit the pay. This gives a smooth consistency and firmness.
confirm that it is done (chop with a toothpick or fork. comes out clean it is already done!) carefully take it out of the oven and let cool slightly, then put it about 10 minutes in the refrigerator.
garnish with whipped cream and a cherry, or thin slices of lemon.
If you make this pie to serve one day later, refrigerate overnight.
To keep it cool, cover with foil. Although I'm sure will not last long, once you take it out of the refrigerator.