Mix the flour, almonds and sugar in a bowl. Add the egg yolk and butter and knead everything into a smooth shortcrust pastry. Wrap the dough in cling film and let it rest for 30 minutes in the refrigerator.
Preheat the oven to 190 ° C (top-bottom heat). Cut the dough into 4-6 equal parts and shape (one after the other) into rolls approx. 2 cm thick. Cut the rolls into pieces approx. 2 cm wide and shape into small croissants. Place the croissants on a baking sheet lined with baking paper and bake until golden yellow for about 10 minutes. Put 5 sachets of vanilla sugar on a deep plate and turn the croissants while they are still hot. Then let cool on a large plate or platter.
Instead of 5 sachets of light vanilla sugar, you can also use 4 light and 1 bourbon vanilla sugar. More bourbon (I think) tastes too strong.
So that the hot croissants don`t break, I let them lie on the baking sheet for about 1 minute before turning them in the sugar.