Step 2 — Prepare the Custard Filling
Pour the whole milk into a medium saucepan and place it over medium heat. Warm it until it’s just beginning to simmer around the edges — small bubbles forming at the rim, steam rising gently — but do not allow it to reach a full boil.
While the milk is warming, whisk together the egg yolks, sugar, and cornstarch in a large heatproof bowl until the mixture is completely smooth and has turned a pale, creamy yellow. There should be no dry patches of cornstarch remaining.
Once the milk is hot, remove it from the heat and begin pouring it into the egg mixture in a slow, thin, steady stream — no faster than a drizzle — whisking constantly as you pour. This process of gradually adding hot liquid to the egg mixture is called tempering, and it’s what prevents the eggs from scrambling. Once all the milk has been incorporated, return the entire mixture to the saucepan.
Cook over low to medium-low heat, stirring constantly with a wooden spoon or heatproof spatula, until the custard thickens noticeably and begins to leave a clear trail when you drag the spoon through it. This usually takes 5 to 8 minutes. The moment it reaches a smooth, pudding-like consistency, remove the pan immediately from the heat and stir in the vanilla extract.
To prevent a skin from forming on the surface as it cools, press a sheet of plastic wrap directly onto the custard so it sits flush against the surface with no air gap. Allow the custard to cool to room temperature, then refrigerate until you’re ready to assemble the tart. The custard can be made up to a day ahead.
Step 3 — Assemble the Torta
Preheat your oven to 180°C (350°F). Lightly butter a 24 to 26 cm round tart or springform pan.
Remove the chilled pastry dough from the refrigerator and divide it into two portions — roughly two-thirds for the base and one-third for the lid. On a lightly floured surface, roll the larger portion into a circle approximately 3 to 4mm thick and large enough to line the base and sides of the pan with a small overhang. Carefully transfer it to the prepared pan, pressing it gently into the base and up the sides without stretching it. Trim any excess overhang.
Spoon the cooled custard into the pastry shell and spread it into an even, smooth layer. Roll out the remaining portion of dough into a circle roughly the same diameter as the top of the tart pan and lay it gently over the custard. Press the edges of the top and bottom pastry together firmly to seal, then trim any ragged edges. Scatter the pine nuts generously and evenly across the top crust, pressing them very lightly so they adhere during baking.
Step 4 — Bake and Cool
Place the assembled tart in the center of the preheated oven and bake for 35 to 40 minutes, until the pastry is a deep golden brown and the kitchen smells of warm butter and vanilla. The top should look set and feel firm with only the faintest give when pressed gently in the center.
