Chocolate shortbread crust is a perfect contrast to the absolute silkiness of the custard in these little tarts. When I tested these, I just couldn’t stop eating them! You’ll need twenty-four 2-inch tart moulds or you can make one big tart with a 9-inch tart shell.
Chocolate Shortbread Crust
Sift flour, cocoa and salt into a food processor. Set aside.
In a small bowl, whisk together 1/3 cup of sugar and the egg for 2 minutes or until smooth.
Add the cold butter to the flour mixture and pulse until mixture resembles fine cornmeal. Then add sugar and egg mixture and continue to pulse until mixture comes together. Do not over work.
Turn onto a board and form into a disc. Cover with plastic and let rest in fridge for about 30 minutes.
Preheat oven to 350 degrees F.
Roll pastry on a floured surface into a round about 2 mm. thick.
Cut circles with cookie cutters or top of glass to match the size of the tart moulds (2-inch mould work best for the amount of dough that has been made).
Line the moulds evenly, firmly pressing pastry in the moulds.
Poke with a fork and let rest in freezer for about 10 minutes.
Bake in bottom rack of oven for about 15 minutes or until golden.
Let cool to room temperature.
Bring cream to a boil with sugar in a medium saucepan.
In a medium bowl, combine the yolks, lemon juice and zest.
Pour hot cream into yolk mixture and whisk to blend.
With the heat at medium low, place the bowl with the yolk and cream mixture over a simmering water bath. Stir continuously with wooden spoon until mixture thickens and heavily coats the back of a spoon, about 20 to 25 minutes.
Stir in vanilla and butter.
Cover surface with plastic wrap and chill.
Fill tart shells just before serving.
Sprinkle each shell with sugar to cover surface. Caramelize the sugar with a blow torch or under a broiler