Orange Curd Tartlets

In a large heatproof bowl, whisk the egg yolks lightly.
In a medium saucepan, stir together the sugar and cornstarch. Whisk in the zest and juice until the sugar and cornstarch are dissolved. Cook over medium heat, whisking vigorously, until thickened and just beginning to bubble, about 2 minutes.
Slowly pour the hot orange mixture into the egg yolks in a thin stream while whisking vigorously in order to heat the yolks gradually and gently. Once the hot mixture has been whisked into the yolks, pour and scrape everything back into the saucepan. Cook over medium-low heat, whisking constantly, until it comes to a gentle boil, lowering heat if necessary so it doesn’t burn. Continue to cook and whisk until thickened, about 30 seconds.
Remove the curd from the heat and whisk in the butter, 1 or 2 cubes at a time, until all the butter is incorporated and the curd is smooth and thick. If desired, strain the curd through a fine-mesh sieve, pressing with a spatula or the back of a spoon. Scrape the curd into a bowl or large measuring cup and cover with plastic wrap, pressing the wrap directly onto the surface of the curd to keep a skin from forming. Let cool to room temperature before refrigerating for several hours or, preferably, overnight.

In a medium bowl, stir together 1 1/4 cups flour, baking powder, salt, and coconut. In a large bowl with an electric mixer, beat the butter and sugar until smooth and creamy, 2 to 3 minutes. Beat in the egg and zest.
Beat the flour mixture into the butter mixture in 2 additions until completely mixed, about 1 minute. Turn the dough out onto a work surface floured with 1 tablespoon flour and gently knead just until the flour is absorbed and a smooth, soft but not sticky dough forms. Wrap in plastic wrap and refrigerate until firm, at least 20 minutes.
Lightly butter 8 individual 3-by-1-inch (7 1/2 cm) round tartlet tins and place them on a rimmed baking sheet.
Divide the dough into 8 equal portions and roll each portion into rounds more than 1/8-inch (1/4 cm) thick. Line the tartlet tins, carefully lifting the dough, pressing it into place, and pinching together any tears in the soft dough. Trim any excess dough above the edges. Refrigerate the tartlet shells while the oven preheats.
Preheat the oven to 400°F (200°C).
Line each shell with parchment or foil, fill with pastry weights or dried beans, and bake for 6 minutes. Carefully lift out the weights and parchment, and return the shells to the oven, uncovered, until golden brown, 8 to 12 minutes. Let cool completely on wire racks.

You will be placing a single orange atop each tart so you want to make sure the orange you choose for candying is not wider than the inside of the pastry shell. Using a very sharp knife, cut the ends off of the orange, about 1/2 to 1 inch (1 to 2 cm). Cut the orange into 8 very thin, very ven slices, each about 1/8 inch (3 mm) thick.
In a pan wide enough to hold all the orange slices in a single layer, combine the sugar and water. Bring to a gentle boil over medium heat and boil until the sugar has dissolved, about 2 minutes. Slide the orange slices into the liquid. Continue cooking at a simmer, carefully turning the slices every few minutes, until the orange pith and rind is soft and fairly translucent and there is only a thin layer of syrup remaining underneath the oranges, 11 to 13 minutes. Remove from the heat and let cool completely in the pan.
When you are ready to assemble the curd tarts, carefully lift the slices from the pan and place them on a plate. Drizzle any remaining syrup in the pan over the orange slices.

Gently pop the pastry shells out of the tins and place on a rack or serving platter. Remove the curd from the refrigerator and beat briefly to loosen and smooth. Divide evenly between the pastry shells and smooth the tops. Top each tartlet with 1 candied orange slice and dust with more coconut, if desired. Serve the orange curd tarts immediately or keep stored in the refrigerator until ready to serve.