Preheat oven to 375°F
Unroll one package crescent rolls and press into greased bottom of 13x9-inch pan, sealing seams and perforations.
Bake for 8-10 minutes or until golden brown.
Layer with half the cheese and all of the corned beef. Combine sauerkraut and dressing and spread over beef. Top with remaining cheese.
On a lightly floured surface, unroll second package crescent rolls and shape into 13x9 rectangle, sealing seams and place over the cheese.
Brush with egg white and sprinkle with caraway seeds. Bake for 12-16 minutes, until crust is golden brown.
Let stand 5 minutes before cutting into squares.