Preheat oven to 375°F. Line a muffin pan with cupcake liners.
Place 1 cup flour, butter, and confectioner’s sugar in a mixing bowl.
Using a pastry cutter, blend butter, flour and sugar into a coarse crumbly mixture.
Add egg, vanilla extract, and ice cold water into the mixture, mix until it forms a dough. If the dough is too wet and sticks, add more flour a tablespoon at a time. If it is too try, add ice cold water a tablespoon at a time.
Roll out the dough to about ⅛ inch thick. Use a round cookie cutter, cut out 12 rounds. You can use a fluted cutter or gently press a fork into the edge for decoration. Place in the cupcake wrappers or straight into the cupcake pan.
Egg Filling
In a sauce pan, heat water and sugar over low heat until the sugar dissolves. Let cool to room temperature.
In a mixing bowl, beat the eggs lightly. Add evaporated milk and vanilla. Beat until well combined. Strain into the sauce pan with cooled syrup. Mix.
Strain the egg mixture into each tart shell, taking care not to over fill them.
Bake the tarts in the oven at 375°F for about 15 - 20 minutes. until the filling rises and the crust is lightly brown.