Shortbread preparation with bimby
Put all the ingredients in the bimby with the cold butter from the fridge and work 30 sec. speed 3/4 then distribute the crumbs evenly distributed on a tray and keep in the fridge for an hour. In the absence of the bimby, a kitchen cutter will be fine because it doesn't have to be a dough, but a set of crumbs.
Shortbread preparation with planetary mixer
quickly sand the flour with the cold butter cut into small pieces, add the sugar, the egg yolk, the aromas and mix very quickly, creating not a dough but a set of crumbs. Spread the crumbs on parchment paper in a tray and leave in the fridge for at least 60 minutes.
Line the bottom of a 24cm cake tin with just over half of the crumbs. Better if on oven paper flattening slightly and creating the edges. Arrange the jam, and cover with the remaining crumbs and cook in the oven at 200° static until cooked for about 40 minutes.