1eggbeaten with 1 tablespoon water, for brushing over the crust
For the crust, place the flour, confectioner's sugar, and salt in the bowl of a food processor and pulse to combine. Scatter the pieces of butter over the flour mixture. Pulse until the mixture resembles coarse yellow meal without any white powdery bits remaining, about 20 pulses. Transfer the mixture to a large mixing bowl. Beat the egg yolks with the cream and vanilla and pour them into the flour-butter mixture. Toss with a spatula until the dough clumps together. If the dough is dry, add 1 more tablespoon heavy cream (better too wet than too dry). Divide the dough in half, form into disks, wrap in plastic wrap, and chill at least 2 hours or up to 3 days.
Just before you are ready to roll out the dough, prepare the filling. Warm the golden syrup in a saucepan until it is runny, or microwave it for 1 minute. Combine the golden syrup, bread crumbs, lemon zest, and lemon juice in a mixing bowl and mix well.
Preheat the oven to 400F. Remove the dough from the refrigerator. On a floured surface, roll out the larger disk to an 11-inch circle. Fold it into quarters, brush off the excess flour with a pastry brush after each fold, then unfold it into a 9-inch tart pan, easing the sides gently into the pan and pressing the dough into the fluted edges. Trim the dough even with the rim. Roll out the second disk 1/8-inch thick. Cut the dough in long strips for the lattice topping.
Scrape the filling into the prepared crust and smooth the top with a rubber spatula. Lay half the strips of dough over the filling in one direction and the other half in the opposite direction to form a lattice. Trim the overhang. Gently brush the beaten egg over the lattice.
Bake for 10 minutes, then reduce the temperature to 375F and bake another 25 minutes until the crust is browned and the filling puffs up in the centre. Serve warm with custard or whipped cream. Serves 8.
Tart dough is hard to roll out because it is sticky and tears easily. Make sure the surface you work on is generously floured. If the dough sticks, simply scrape it off, clump it back together, and reroll it. If the dough breaks or tears, don't worry. You can easily patch it in the pan with extra pieces of dough and a bit of water.(Recipe used with written permission from the author. Copyright Adams Media 2012.)