03Meanwhile, whisk together the eggs, sugar, lemon zest, lemon juice and flour. Pour over the warm crust and bake for 30 to 35 minutes, until the filling is set. Let cool to room temperature (or refrigerate overnight in the pan). Using the parchment to pull it out of the pan, transfer to a cutting board and peel the paper down. Using a sharp knife or pizza cutter, cut into 20 squares. Then cut each square diagonally to form 40 triangles. Sprinkle with powdered sugar before serving.