In a bowl, whisk together the all-purpose flour, hazelnut meal and salt.
In the bowl of an electric mixer fitted with the paddle attachment, combine the butter and confectioners’ sugar. Mix on medium-low speed until well combined, about 4 minutes.
Mix in the egg and then the yolk, allowing each to be incorporated before adding the next. In two additions, add the flour mixture, scraping down the sides of the bowl after each addition. If it seems dry and crumbly, not to worry, using your hands knead the dough until it comes together, it might take about a minute or so.
Turn out the dough onto a clean lightly floured work surface. Divide it in half, shape into flattened disks, and wrap each one in plastic wrap. Refrigerate for at least 1 hour, or overnight. (The dough can be frozen for up to 1 month; thaw it overnight in the refrigerator before using.)
Preheat your oven to 350 degrees F. Liberally flour your work surface and rolling pin. Remove one of the discs from the refrigerator and place on the counter. If the crust is too cold to roll out, allow it to come to room temperature, slightly, for about 10 minutes. Roll the crust out, being sure to turn it every so often so it doesn’t stick to the counter (this dough is a bit sticky), and adding more flour for dusting, when needed.
Roll the dough onto the rolling pin and transfer it to a 9-inch tart pan). If the dough falls apart a bit, not to worry. (Mine had a bit of cracking.) Take the scraps and press it into the dough, sealing any cracks or holes, and then trimming the overhang.
Using a fork, score the bottom of the tart crust. Transfer it to the freezer to chill for 15 minutes. Line the tart with foil or parchment paper and fill with pie weights or pennies. Transfer to the oven to bake for 15 minutes. Remove the foil and pie weights and bake for an additional 15 minutes, or until tart crust is lightly golden brown. Allow to cool to room temperature.