The dough gets made up to a day ahead of baking so don’t preheat your oven first. I highly suggest weighing out your ingredients using grams with a kitchen scale. It will be much more accurate and taste better. 

In a large mixing bowl whisk together the flour, salt, sugar and vanilla sugar. Add in the butter and egg yolks and mix until you get a cohesive dough. You can use a wooden spoon or spatula.

Next, make sure hands stay cool as you knead the dough together until smooth. This can be done in the bowl or on a clean, flat surface. 

Split the dough into two portions and shape each into a disc, wrap each disc in plastic wrap, then chill 4 hours up to overnight. Overnight is best. You can also freeze the dough - just thaw overnight in refrigerator before baking.

When ready to bake, heat oven to 350 Deg F and line baking sheets with parchment paper.

Bring dough to cool room temperature, takes about 20 minutes for refrigerated dough. 

Working with one disc of dough at a time, roll out between pieces of wax paper to between ⅛ and ¼ inch thick (3-6mm thick).  Err on the side of thicker. Dip your cookie cutter lightly in flour then cut out and place on prepared baking sheets using a spatula.. Chill the dough for 10 minutes ( either refrigerator or freezer). 

Bake for 10 minutes or until dry on top and firm but not turning golden. These are pale when fully baked. 

Let cool for 5 minutes on baking sheets then transfer to wire cooling racks to cool completely. 

When ready to decorate melt the white chocolate ( I prefer double boiler method best) and you can either dip the cookie tops in chocolate or spread on thinly with a small spatula. Sprinkle with the candy cane pieces and let dry completely.

I will place the decorated cookies on a parchment lined baking sheet and set in the refrigerator or freezer to firm up the chocolate. Once all decorated and the chocolate is set, store cookies in an airtight container at either cool room temperature or in the refrigerator or freezer.  Serve at room temperature.