In a bowl of your electric mixer combine flour, butter, vanilla extract, sugar and egg yolk.
Turn on your mixer and stir until all ingredients are combined and you get a smooth, soft dough. Wrap it up in plastic and refrigerate it for about 1 h.
When chilled, put it on your kitchen counter, dusting it slightly with some flour and roll each piece into a ball. Then using you finger, press gently in the center. Refrigerate for 30 more min, then bake at 200 c for 15 min. Let the cookies cool down on a wire rack.
Than grab some Amarena Fabbri and place one right in the center of each cookie. Serve or store in a glass container for a couple of days.