Vanillekipferl (German Vanilla Crescent Cookies)

Method

1. 1Mix the dry ingredients. Put the flour, ground almonds, the first 80 g of powdered sugar and the salt into a wide bowl. Split the vanilla pod lengthwise, scrape out the seeds with the back of a knife and rub them into the flour with your fingertips so they do not stay in clumps. Keep the empty pod: it goes into the sugar jar later.
2. 2Bring the dough together fast. Cut the cold butter into 1 cm cubes and add it with the egg yolks. Rub and press everything together with your hands for 2 to 3 minutes, only until no dry flour is left and the dough holds in one piece. Stop there. Every extra minute warms the butter, and warm butter gives greasy dough and crescents that spread flat in the oven.
3. 3Chill. Divide the dough in two, roll each half into a log about 3 cm thick, wrap and refrigerate for at least 1 hour, or overnight. The cold is what lets you bend the crescents without cracking them and keeps their shape in the heat.
4. 4Heat the oven to 180°C top and bottom heat (160°C fan). Line two or three baking trays with paper. Stir the second 80 g of powdered sugar with the vanilla sugar in a shallow dish and set it next to the stove.
5. 5Shape. Take one log out of the fridge and leave the other inside. Slice it into discs 1 cm thick, about 10 g each. Roll each disc under your fingers into a finger 5 to 6 cm long with thinner, tapered ends, then bend it into a crescent straight on the tray, 2 cm apart. If the dough cracks as you bend it, it is too cold: hold the piece in your palm for a few seconds. If it sticks and smears, it is too warm: back into the fridge for 10 minutes.
6. 6Bake one tray at a time on the middle rack for 11 to 13 minutes. The crescents must stay pale: only the tips should turn light gold. Browned Vanillekipferl taste of toasted nuts and lose the melting texture they are made for.
7. 7Sugar them at the right moment. Leave the tray to stand for 2 to 3 minutes. Straight from the oven the cookies break at a touch; after ten minutes the sugar no longer sticks. Then roll them gently, a few at a time, in the vanilla sugar, or sift the sugar thickly over them on the tray if they feel fragile. Cool completely on a rack, dust once more and layer in a tin with baking paper between the layers.