Preheat oven to 375° F.
In medium bowl, cream together the butter, white sugar and egg yolks. Mix in flour a little at a time until a soft dough forms.
Roll dough into 1 inch balls. Place balls 2 inches apart on parchment-lined cookie sheets and flatten balls into rounds. Refrigerate for 30 - 60 minutes.
When thoroughly chilled, cut holiday designs into half of the rounds. Dice the apple filling and place the filling on the uncut round. Place the cut rounds on top of the un-cut rounds and gently gather the edges together.
Bake for 8-10 minutes until golden brown on the bottom. Remove from cookie sheets to cool on wire racks.