Cream the butter and add sugar. Mix.
Add egg yolks, mixing in one at a time. Add vanilla.
Add the flours, salt and baking powder until combined.
Chill for at least one hour.
Preheat oven to 325°F
Roll out dough and cut out as many rectangle shapes as possible. With small heart, diamond, spade and club shapes, cut into the center of half of the rectangles. The whole rectangles will be the bottom cookies, the rectangles with 'windows' will be the top cookies, centered by jam.
Bake until the edges begin to golden, about 8-10 minutes.
Let the cookies cool completely, then spread jam onto the whole rectangles: raspberry for the diamond and hearts, blackberry for the spades and clubs. Using a small sifter, sprinkle the confectioners sugar on top of the cookies with the centers cut out. Place these on top of the cookies covered in jam. Enjoy!