Spread dressing evenly on 1 side of each bread slice; top half of slices evenly with half of cheese, corned beef, sauerkraut, and remaining cheese. Top with remaining bread slices.
Coat a baking sheet with cooking spray; arrange sandwiches on baking sheet. Coat bottom of a second baking sheet with cooking spray; place, coated side down, on sandwiches.
Bake at 375° for 8 to 10 minutes or until bread is golden and cheese melts.
Note: To make ahead, place unbaked sandwiches on baking sheets and freeze until firm; place sandwiches in heavy-duty zip-top plastic bags, and freeze. Bake according to directions at 375º for 15 minutes.