Cut the butter into the flour until it resembles coarse crumbs. Add egg yolks and vinegar, then water. Mix well. Cover and refrigerate at least one hour.
Divide dough in half. Roll each half into an oval on a lightly floured board.
To fill, make inch-long cuts along the long edges of the oval. Add the filling in a stripe along the center. Pull the snipped pieces over the middle, alternating sides. Press the dough strips together along the top.
Bake at 350 degrees for 45 minutes. Filling should be bubbly and crust should be lightly golden.