If we have a food processor or grinder, the dough will be ready in a jiffy. It can also be done with a stick blender or by hand, although this way we can overheat the ingredients if it’s a bit hot in the kitchen.
Cut the cold butter into small cubes and place in the processor with the flour, salt, vanilla sugar, sugar and egg. Blend until smooth. If the processor is small we can leave the egg and sugar for last.
Transfer the dough to a clean work surface and finish working with your hands until smooth. It should be smooth and even, almost not sticky. Wrap in plastic film and leave 30 minutes in the fridge. If it’s cold, you may not even need to rest.
Preheat the oven to 180º C and prepare a couple of trays with parchment paper, or grease them. To make the large spiders we will need portions of about 20 g of dough, although they can be made a little by eye. form balls and distribute them on the trays, a little apart.
Flatten by hand into thick discs and, using your finger, the handle end of a wooden ladle or small mortar mallet, make small holes in the center. Bake for about 10 minutes, carefully remove and go over the hole by gently squeezing. It should be adjusted to the diameter of the chocolates, approximately.
Return to oven until golden brown, about 10 minutes more. Wait a bit before transferring the cookies to a rack. We can take advantage of when they are still hot to put the chocolates, this way the base will melt a little and they will stick. Be careful, if they are very hot we will have melted spiders. Put in the fridge to chill the chocolate.
To finish the decoration, you only need to melt a tablet of dark chocolate and, with the help of a pastry bag or pastry pencil, glue the eyes and draw the legs, four on each side. If we don’t have sugar eyes we can improvise them by also melting white chocolate. Today they are easy to find, and more so at this time, in specialized physical or virtual confectionery stores. Some examples are María Lunarillos, Megasilvita, Comercial Mínguez, or Amazon.