Preheat oven to 375˚F
Cream together butter, sugar, and egg yolks.
Mix in flour mixing until a soft dough forms.
Pinch off pieces and roll dough balls in your palms to make 1 inch balls.
Place balls on cookie sheet and make a well in the center.
Fill each well with 1/2 tsp jam
Bake for 8-10 minutes until golden on the bottom.
Remove and cool on wire rack--Jam is HOT, be sure to cool.