Preheat the oven to 500 degrees
Grease a muffin pan with butter (to make 8 tarts)
Unfold pie crust or puff pastry and cut out 8 four-inch rounds (you may have to roll the crust a couple of times to get 8.
Insert each pie crust round into a muffin tin to create a cup for the custard, pressing in each tin from the center to the brim. If you use filo dough, simply line the muffin tins with it Layering each layer with butter.
Mix the cream and milk in a large saucepan
Add the grated lemon peel
Whisk the egg yolks
Blend in the cornstarch
Blend in the sugar.
Heat on a low heat until the mixture comes to a boil.
Take the mixture off the heat.
Pour the mixture into 8 muffin tins
Place the muffin pan in the oven and bake for 15 minutes or until the pastry and cream is lightly browned.
When the pastries are done let them cool.
Mix together the powdered sugar and cinnamon
Using a sifter, lightly sprinkle the tarts with the sugar and cinnamon mixture
Serve the tarts lukewarm