For the pasta frolla, combine the dry ingredients in a bowl and mix well. Rub in the butter until it is absorbed, making sure the mixture remains cool and powdery and does not become pasty. Beat the egg and milk or water together and stir in with a fork. Continue stirring until the dough holds together, then knead it briefly, just until smooth. Shape into a disk, wrap in plastic, and refrigerate at least 1 hour, or until firm.
For the lemon filling, bring the milk to a boil with the lemon zest and half the sugar in a
Whisk the yolks in a bowl with the salt and whisk in the remaining sugar in a stream. Sift the flour over the mixture and whisk in. Whisk in the vanilla and lemon juice.
When the milk boils, remove from the heat and whisk one-third of it into the yolk mixture. Return the remaining milk to a boil and, beginning to stir the milk first, pour in the yolk mixture. Continue stirring constantly until the cream thickens and comes to a boil. Allow to boil, stirring constantly, for 30 seconds.
Remove from the heat and pour into a clean nonreactive bowl. Press plastic wrap against the surface and refrigerate until cold.
Bake at 350 degrees for about 45 minutes, until the filling is set and the pastry is a light gold. Cool in the pan before unmolding. To unmold, invert onto a flat plate, lift off the pan, replace the pan with another plate or platter, then reinvert so that the torta is right side up. Serve the torta at room temperature.
© 1990 Nick Malgieri. All rights reserved.