Pastéis de Nata (Portuguese Egg Tarts)

Cut 1 1/2 sticks unsalted butter into 12 pieces and let sit at room temperature until softened, about 1 hour.

Place 1 3/4 cups all-purpose flour and 2/3 cup water in a large bowl and mix with your hands until a shaggy dough forms. Knead until dough is elastic but still a little tacky, about 5 minutes. Form the dough into a ball, wrap in plastic wrap, and let rest for 20 minutes.

The dough should now look very smooth. Generously flour a clean work surface, a rolling pin, and the dough. Roll the dough out into an 8x10-inch rectangle about 1 centimeter thick with a long side closer to you.

Brush any excess flour off the dough. Spread 3 pieces of the butter in a thin layer onto the left 2/3 of the rectangle. Lift up the right unbuttered portion and fold it over the middle section, then fold the far left panel over the middle. Rotate the dough 90 degrees. Roll the dough out again into an 8x10-inch rectangle. Repeat buttering, folding, rotating, and rolling out the dough two times more. Spread the remaining butter on the dough, leaving a 1/2-inch border.

Starting with the long side closest to you, tightly roll the dough up into a log. Trim both ends, then cut the log in half crosswise. Wrap one piece in plastic wrap and refrigerate for 30 minutes. Wrap the other and freeze for future use.

Arrange a rack in the top third of the oven and heat the oven to 550°F or as high as it'll go. If your oven doesn’t heat up to 550°F, place a pizza stone or 2 stacked baking sheets on the top rack while the oven heats.

Using a vegetable peeler, peel 2 long strips zest from 1 medium lemon, being careful not to peel off any of the white pith. Place the zest, 1 1/3 cups granulated sugar, 2/3 cup water, and 1 cinnamon stick in a small saucepan. Bring to a boil over medium-high heat. Simmer, swirling pan occasionally but not stirring, until thickened to the consistency of syrup, about 3 1/2 minutes. Measure out 7 fluid ounces of the syrup and set aside.

Place 1/3 cup of the whole milk and 1/4 cup of all-purpose flour in a medium bowl and whisk until no lumps remain. Bring the remaining 1 cup whole milk to a boil in a medium saucepan over high heat. Remove the saucepan from the heat. While whisking constantly, slowly pour half of the hot milk into the flour mixture. Pour the mixture back into the saucepan. Add the measured syrup and cook over medium heat, stirring constantly, until thickened and smooth, 3 to 5 minutes. Remove the saucepan from the heat.

Place 5 large egg yolks in the now-empty milk-flour bowl and whisk to combine. Temper the eggs by slowly whisking half of the hot milk into the eggs. Pour the mixture back into the saucepan and set aside.

Cut the chilled dough crosswise into 12 discs about 1/2-inch thick. If your kitchen is warm, shape one at a time and refrigerate the remainder. Place the disc in an egg tart tin or a well of a standard muffin tin. Use your thumb to firmly press the center against the bottom of the tin, forming a wall of dough around your thumb. If using egg tart tins, press the edges of the dough outward until it extends over the lip of the tin by 1/4 inch. If using a muffin tin, the dough will not reach the tops of the cups. Make sure the dough is as thin as you can get it. If the dough is sticking to you, dip your thumb in water before shaping.

Place the dough-lined tins on a baking sheet. Fill the tins or wells with the custard up to 1/4 inch from the top. Bake until the custard is slightly puffed and browned in spots and the crust is golden-brown and revealing its layers, 10 to 16 minutes. Let the tarts cool for 10 minutes, then carefully unmold them onto a wire rack.

Dust with a little powdered sugar and ground cinnamon right before serving if desired.