Make double recipe, each batch makes 1.25 trays.
Make cookie dough and roll in wax paper, chill overnight.
1 cup butter
1 cup powdered sugar
2 egg yolks
2.5 cups unsifted flour
—
Mix dough, divide in half, roll into 1.5″ rolls, slice 0.25″ thick. Bake 300 degrees for 20-25 min.