Grandmother's Custard Jewel Tart

Make the pasta frolla (shortcrust) by combining the flour, 1/2 cup sugar, baking powder, salt, and lemon zest in a food processor. Pulse a few times to mix.

Add the cold cubed butter and pulse in short bursts until the mixture resembles coarse breadcrumbs with some pea-sized pieces remaining.

Add the 2 egg yolks and whole egg through the feed tube while pulsing, just until the dough starts to clump together. Do not overwork. Turn out onto plastic wrap, press into a disc, and refrigerate for at least 1 hour.

For the crema pasticcera, heat the milk with the lemon zest in a medium saucepan over medium heat until steaming and just beginning to bubble at the edges. Do not boil.

In a separate bowl, whisk the 4 egg yolks with 1/2 cup sugar until pale and thick, about 2 minutes. Whisk in the cornstarch until smooth.

Slowly pour the hot milk into the egg mixture in a thin stream, whisking constantly to temper the eggs without scrambling them.

Return the mixture to the saucepan and cook over medium heat, stirring constantly with a wooden spoon or silicone spatula, until the custard thickens dramatically and begins to bubble, about 3-4 minutes.

Remove from heat and stir in the vanilla and 2 tablespoons butter until melted and smooth. Press plastic wrap directly onto the surface of the custard to prevent a skin from forming. Refrigerate until completely cool, at least 1 hour.

Preheat the oven to 350F. Butter and flour a 9-inch tart pan with a removable bottom.

Divide the chilled dough roughly 60/40. Roll the larger piece on a lightly floured surface into a circle about 12 inches in diameter. Fit it into the tart pan, pressing gently into the corners and up the sides. Trim any excess.

Whisk the chilled custard to loosen it, then spread it evenly into the pastry shell, smoothing the top.

Roll the remaining dough into a circle large enough to cover the top. Drape it over the custard, pressing the edges to seal with the bottom crust. Trim excess and crimp decoratively.

Scatter the pine nuts evenly over the top crust and press them in gently.

Bake for 30-35 minutes until the crust is a deep golden brown and the tart feels set when gently jiggled.

Cool in the pan for 15 minutes, then remove the ring and transfer to a serving plate. Dust generously with powdered sugar before serving.