Put the flour, sugar, and salt in a large bowl and mix together. Cut the cold butter into small pieces and carefully rub them into the flour mixture, a little at a time, with your fingers. Now add the cold milk, egg and all the spices.
Knead the dough quickly until it is homogeneous, form a ball and chill it covered for at least 2 hours. For best results, chill the dough overnight, i.e. for a good 12 hours.
Then preheat the oven to 375° F.
Take the dough out again and roll it out evenly on a floured surface. Cut out the speculoos with suitable moulds, or use a practical wooden embossing roller. You can also simply cut rectangles or squares.
Place the speculaas on a baking tray lined with baking paper and bake in the preheated oven for about 10–12 minutes. They will still be slightly soft, but will firm up when they cool.