Rub the butter into the flour. In a large mixing bowl, sift the flour, confectioners’ sugar and salt. Add the butter and toss until the cubes are coated. Rub the mixture together between your fingers until it reaches a breadcrumb consistency with a few hazelnut-sized pieces of butter still visible.
Add egg and water. Make a well in the centre and add the egg. Using a fork, mix the egg into the flour. Add 1 tablespoon (15 ml) of the ice-cold water, and use your fingertips to bring the dough together. If the dough isn’t clumping together, add more water sparingly. Tip the dough onto a lightly floured countertop, and use floured hands to shape the dough into a ball, taking care not to overwork it. Flatten slightly into a disc, and wrap well in plastic wrap. Place in the fridge for at least 1 hour to let the dough rest.
Bring the dough together and refrigerate. Tip the dough onto a lightly floured countertop, and use floured hands to shape the dough into a ball, taking care not to overwork it. Flatten slightly into a disc, and wrap well in plastic wrap. Place in the fridge for at least 1 hour to let the dough rest.
Roll out dough. Remove the chilled dough disc from the fridge and set it aside on your countertop for 15 minutes or so to allow the dough to warm up slightly so it’s easier to roll out. Trying to roll dough that is too cold will cause the edges to crack. To roll out, lightly flour your countertop and rolling pin, and using firm, even strokes, roll from the centre outward, turning the dough a quarter turn every few strokes. Roll the dough out to the thickness of a coin (⅛-inch (3-mm) thick) and into a 12-inch (30-cm) circle.
Prepare dough in the tart tin. Flour the base of a 9-inch (23-cm) shallow fluted tart pan with a removable base, and gently lift the dough and place it into the prepared pan. Use your fingers to push the dough up the sides of the pan and into the grooves. Using a sharp knife, trim off the excess dough from the rim. Refrigerate the prepared tart shell for at least 1 hour to allow the dough to relax further. (My preference is to leave the shell overnight in the fridge and continue with the recipe the next day. If you do this, cover it well in plastic wrap to ensure that the dough doesn’t dry out.)
Blind bake. Preheat the oven to 350°F (180°C). Once the dough is chilled, prick the tart base all over with a fork, and then line with parchment paper and fill with pie weights all the way up the sides. Blind bake for 15 minutes, and then remove the parchment paper and pie weights. Return the tart back to the oven and bake for 7 to 10 minutes, or until the base is dry and a light golden colour. Remove from the oven, and leave the tart shell to cool whilst you make the caramel and prepare the filling.