Similar to its standard mini version, this extra large Portuguese custard tart is a fun twist on the classic pastry. The flakey, crisp crust filled with rich, velvety custard slices up beautifully to feed a small crowd. Even in the larger size, this tart keeps the signature browned top and crunchy edges by being baked in an extra hot oven (and by blind baking the puff pastry shell before adding the filling). A hint of cinnamon in the heavenly pastry cream is all you really need, but feel free to serve with a dusting of confectioner’s sugar, a side of ice cream or a warm cup of coffee.
Combine the sugar and water in a small saucepan and bring to a boil. Simmer the syrup for about a minute or so, then remove from the heat to let cool.
Add 1 cup of the milk to a large saucepan. Heat over medium heat until the milk begins to steam and small bubbles begin to form around the edges.
Meanwhile, whisk together the remaining 1/2 cup of milk, flour, cinnamon, and salt in a large mixing bowl until a smooth paste forms. In a separate bowl, whisk together the egg yolks and set aside.
Once the milk is warm, gently stream about half of the warm milk into the flour mixture, while stirring. Stir in the remaining milk and sugar syrup. Whisk to eliminate any lumps. Add in the egg yolks and whisk to combine.
Pour all of the ingredients back into the large saucepan and place over medium-low heat. While stirring, heat the mixtures until it thickens and large bubbles begin to pop at the surface. Always keep stirring slowly, and be sure not to let the mixture curdle.
Strain the custard into a heat-safe bowl. Stir in the vanilla and cover by pressing a piece of plastic wrap directly to the top surface of the custard. Refrigerate until thickened and ready to use, or overnight.
Pre-heat oven to 375ºF. Gently unfold the thawed puff pastry on a lightly floured surface. Trim the puff pastry into a square that is about 3 inches larger than your round tart pan (an 11-inch square for an 8-inch round tart pan). Gently lift and fit the puff pastry into the tart pan. Press the dough into the pan. Trim the excess dough by rolling over the top edge of the tart pan with a rolling pin, paring knife, or kitchen shears.
Dock the dough to the bottom of the pan by pricking it with a fork. Be sure to prick any surface you wish to keep from “puffing” up including to crease between the bottom and sides of the pan. Chill in the refrigerator for 15 minutes.
Brush on side of a piece of foil with butter and line the chilled dough with it, butter-side down. Fill the pan with pie weights and bake for 10 minutes. After 10 minutes, carefully remove the foil/weights and return to the oven for 2 minutes.
After the 2 minutes, gently press down the center of the tart shell with a clean kitchen towel if it has puffed up at all. Allow to completely cool.
Increase the oven to 450ºF.
Once the tart shell has cooled (keep it in the pan), fill it with the custard. Place the filled tart on a rimmed baking sheet and into the pre-heated oven for 25 to 28 minutes. When done, the center should be partially browned and the crust should be cooked. If at any time the crust begins to brown too quickly, cover the edges with foil (most likely halfway through the bake).
Allow to cool before slicing. Best served the day that the tart is made.